how is -x^6+7x^5 considered a sixth degree binomial?

Answers

Answer 1

Answer:

Polynomial, 6. Constant. The highest value of the exponent in the expression is known as the Degree of Polynomial. The degree of a polynomial is the largest exponent. It is also known as an order of the polynomial. While finding the degree of the polynomial, the polynomial powers of the variables should be either in ascending or descending order.

Step-by-step explanation:

Answer 2

A term is defined as a part of an equation separated by a +/- operation. Because there is a + operation separating two terms (-x^6 and 7x^5), the expression is a binomial, meaning the expression has two terms.

The highest exponent or degree, present in the expression is to the power of 6. Therefore, the expression is in the sixth degree.

Taken together, the expression is a sixth-degree binomial.


Related Questions

3. Omar chooses a marble at random from the bag shown below. Without putting
the first marble back, he chooses another marble.
What is the probability that Omar chooses two blue
marbles? Express your answer as a fraction in lowest terms.

Answers

Answer:

Theres no bag we cant solve it without you showing a picture or describing it

Step-by-step explanation:

Work out (4 x 3)² ÷ 6

Answers

An expression is defined as a set of numbers, variables, and mathematical operations. The solution of (4 x 3)² ÷ 6 is 24.

What is an Expression?

In mathematics, an expression is defined as a set of numbers, variables, and mathematical operations formed according to rules dependent on the context.

The solution of the expression (4 x 3)² ÷ 6 is,

(4 x 3)² ÷ 6

= (12)² ÷ 6

= 144 ÷ 6

= 24

Hence, the solution of (4 x 3)² ÷ 6 is 24.

Learn more about Expression:

https://brainly.com/question/13947055

#SPJ1

twice a number increased by 8 is 20. find the number​

Answers

Answer:

Answer is 6

Step-by-step explanation:

Let the number be ×

Twice a number is 2×

Twice a number increase by 8 is 2×+8

hence the equivalent will be

2×+8=20

2×=12

×6

Answer:

6

Step-by-step explanation:

Let n be the unknown number.

"Twice a number" means to multiply the number by 2:  

⇒ 2n

"Increase by 8" means to add 8:

⇒ 2n + 8

"Is 20" means equals 20:

⇒ 2n + 8 = 20

Therefore, the equation is:  2n + 8 = 20

To solve, subtract 8 from both sides:

⇒ 2n + 8 - 8 = 20 - 8

⇒ 2n = 12

Divide both sides by 2:

⇒ 2n ÷ 2 = 12 ÷ 2

⇒ n = 6

Therefore, the unknown number is 6.

Please answer this question!! <3 <4 <5 <6 <9

Answers

The correct answer is option C which is the angle LMO is 50°

What is trigonometry?

The branch of mathematics sets up a relationship between the sides and the angles of the right-angle triangle termed trigonometry.

Given that:-

∠O = 70°

∠L = 60°

∠LMO =?

As we know that the sum of the three angles are 180 degree applying this relation:-

∠LOM + ∠OLM  + ∠LMO = 180

70 + 60 +  ∠LMO = 180

∠LMO = 180 - 70 - 60 = 50

Therefore the correct answer is option C which is the angle LMO is 50°

To know more about Trigonometry follow

https://brainly.com/question/24349828

#SPJ1

juan tiene 400 y rosa 350. ambos se compran

Answers

Juan has 400 and pink 350. Both are bought ….

How much acetic acid is in a 5 - liter container of acetic acid and water that is marked 80% acetic acid ? How much is water ?

Answers

I think the question ur asking is what’s the volume of water?? If so then the volume of water is 1L

Which of the following is a list that follows this pattern with its numbers: prime, prime, prime, composite, prime, prime 1, 5, 7, 9, 11, 13 1, 2, 5, 7, 9, 15 2, 4, 6, 8, 10, 12 11, 9, 3, 2, 5, 4, 8

Answers

The correct answer is option A which is the pattern {prime, prime, prime, composite, prime, prime} is followed by 1, 5, 7, 9, 11, 13.

What are prime and composite numbers?

Prime numbers:-

The prime number is defined as the number which is divided by 1 and itself.

Composite numbers:-

The number is defined as the composite number when the number is divided by 1 itself and any other numbers also.

From the given options we need to choose the pattern of the series { prime, prime, prime, composite, prime, prime } so we can see that in option A correct pattern is followed.

Pattern { 1, 5, 7, 9, 11, 13 }

1   → prime

5  → prime

7  → prime

9  → composite

11  → prime

13 → prime

Therefore the correct answer is option A which is the pattern {prime, prime, prime, composite, prime, prime} is followed by 1, 5, 7, 9, 11, 13.

To know more about prime and composite numbers follow

https://brainly.com/question/375267

#SPJ1

Two dice are rolled. What is the probability that the sum of the numbers rolled is either 10 or 11? Express your answer as a fraction in lowest terms or a decimal rounded to the nearest millionth.

Answers

Answer:

P(Event) = N(Favorable Outcomes) / N (Total Outcomes)

P(sum of 10 or 11) = 5/36

Step-by-step explanation:

Probability states how likely an event is about to happen. The probability of an event can exist only between 0 and 1 where 0 indicates that event is not going to happen i.e. Impossibility and 1 indicates that it is going to happen for sure i.e. Certainty.

The higher or lessen the probability of an event, the more likely it is that the event will occur or not respectively. For example – An unbiased coin is tossed once. So the total number of outcomes can be 2 only i.e. either “heads” or “tails”. The probability of both outcomes is equal i.e. 50% or 1/2.

So,

P(Event) = N(Favorable Outcomes) / N (Total Outcomes)

Sample Space:

All the possible outcomes of an event are called Sample spaces.

Examples-

• If two dice are rolled together then total outcomes will be 36 and

Sample space will be

[ (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)  

  (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)

  (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)

  (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)

  (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)

  (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) ]

Probability of rolling a sum of 10 or 11 with two dice:

When two dice are rolled together then total outcomes are 36 and

Sample space is

[ (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)

  (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)

  (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)

  (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)  

 (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)  

 (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) ]

So, pairs with sum 10 or 11 are (4, 6) (5, 5) (6, 4) (5,6) (6,5) i.e. total 5 pairs

Total outcomes = 36

Favorable outcomes = 5

Probability of getting the sum of 10 or 11 = Favorable outcomes / Total outcomes

                                                               = 5 / 36

So, P(sum of 10 or 11) = 5/36

Read to see a similar question related to probability:

https://brainly.com/question/743546?referrer=searchResults

#SPJ10

A person buys a used car with a down payment of $1,200 and makes monthly payments of $275 for 3 years.What is the total amount of the person pays for the car?PLEASE EXPLAIN
A.$2,025
B.$9,900
C.11,100
D.13,500

Answers

Answer:

2025 $

Step-by-step explanation:

275 multiply 3 +1200

Answer:

A.$2,025

Step-by-step explanation:

$275 x 3 years + $1,200

= $2,025

what is the name of the shape graphed by the function theta=-4pie/3

Answers

Step-by-step explanation:

On a polar plane, the shape will be a line that goes through the pi/2- pi quadrant , and 3pi/2- 2pi quadrant

On a Cartesian or rectangular plane, the shape will be a line as well passing through 2nd and 4th quadrant

What is the slope-intercept equation for the line below?
10
(0, 2)
(5, 4)

Answers

Answer:slope is 0.4

Step-by-step explanation:

y2-y1 divided by x2-x1

2-4/0-5=0.4

solve for x -
[tex]\bold{x {}^{2} + 5x + 6 = 0}\\\\[/tex]
ty! ~

Answers

The solution of the given quadratic equation is x=-2 or x=-3.

The given quadratic equation is x²+5x+6=0.

What are different methods to solve a quadratic equation?

The different methods of solving quadratic equations are factoring, completing the square or using the quadratic formula.

By using the splitting middle term method we can solve x²+5x+6=0.

That is, x²+2x+3x+6=0

⇒x(x+2)+3(x+2)=0

⇒(x+2)(x+3)=0

⇒(x+2)=0, (x+3)=0

x=-2 or x=-3.

Therefore, the solution of the given quadratic equation is x=-2 or x=-3.

To learn more about the quadratic equation visit:

https://brainly.com/question/2263981.

#SPJ1

Solve the system of equation for y using Cramer's rule. Hint: The determinant of the coefficient matrix is -23.

Answers

Answer:

-4  option (c)

Step-by-step explanation:

Cramer rule : In this method, the values of the variables in the system are to be calculated using the determinants of matrices

if , D :determinant of the coefficient matrix

[tex]{D}_{x}:[/tex]determinant of the matrix with coefficients except x

then,

[tex]x=\frac{{D}_{x}}{D}[/tex]

similarly,

[tex]y=\frac{{D}_{y}}{D}[/tex]

[tex]z=\frac{{D}_{z}}{D}[/tex]

given,

D = -23

[tex]D_{y}[/tex]  =           [tex]det\left[\begin{array}{ccc}5&7&-1\\2&6&-2\\3&-7&2\end{array}\right][/tex]

[tex]D_{y}[/tex] = 92

therefore, y = 92/(-23)

   y = -4 answer

learn more about determinants at

https://brainly.com/question/11841826

#SPJ10

Question 7 of 10
Classify the following triangle. Check all that apply.

Answers

Answer:

A,C,E

(if you find a better answer choose that.)

Step-by-step explanation:

This one has two acute angles and one obtuse.

This one is a scalene.

So, tick A,C,E

Ryan also found that he could model the height of his plant with the equation h = 0.5d + 4, where d is the number of days and h is the height in centimeters. part b question 2

Answers

The domain is  {0, 1, 2, 3, 4, 5, 6} and range is {4, 4.5, 5, 5.5, 6, 6.5, 7}.

What is Domain and Range?

The domain of a function is the set of values that we are allowed to plug into our function.

The range of a function is the set of values that the function assumes.

The complete question is

Ryan also found that he could model the height of his plan with the equation H = 0.5D + 4 where D is the number of days and H is the height in centimeters. Determine the domain and the range for this relationship.

Given:

h = 0.5d + 4

The Domain of the function is: {0, 1, 2, 3, 4, 5, 6}

and the Range is: {4, 4.5, 5, 5.5, 6, 6.5, 7}

Learn more about this concept here:

https://brainly.com/question/17143164

#SPJ1

what is the missing pattern 7, 11, 2, 18, -7

Answers

The missing pattern behind the sequence 7, 11, 2, 18, -7 is described by the formula [tex]n = 7 + \sum \limits_{i= 1}^{n} (-1)^{i+1}\cdot (i + 1)^{2}[/tex], equivalent to the recurrence formula [tex]a_{n+1} = a_{n} + (-1)^{i+1}\cdot (i + 1)^{2}[/tex].

What is the missing element in a sequence?

A sequence is a set of elements which observes at least a defined rule. In this question we see a sequence which follows this rule:

[tex]n = 7 + \sum \limits_{i= 1}^{n} (-1)^{i+1}\cdot (i + 1)^{2}[/tex]      (1)

Now we prove that given expression contains the pattern:

n = 0

7

n = 1

7 + (- 1)² · 2² = 7 + 4 = 11

n = 2

7 + (- 1)² · 2² + (- 1)³ · 3² = 11 - 9 = 2

n = 3

7 + (- 1)² · 2² + (- 1)³ · 3² + (- 1)⁴ · 4² = 2 + 16 = 18

n = 4

7 + (- 1)² · 2² + (- 1)³ · 3² + (- 1)⁴ · 4² + (- 1)⁵ · 5² = 18 - 25 = - 7

The missing pattern behind the sequence 7, 11, 2, 18, -7 is described by the formula [tex]n = 7 + \sum \limits_{i= 1}^{n} (-1)^{i+1}\cdot (i + 1)^{2}[/tex], equivalent to the recurrence formula [tex]a_{n+1} = a_{n} + (-1)^{i+1}\cdot (i + 1)^{2}[/tex].

To learn more on patterns: https://brainly.com/question/23136125

#SPJ1


a telephone company charges $0.98 for the first minute, $0.82 for each additional minute, and a$1.56 service charge if the cost is 11.56 how long did the person talk

Answers

Answer:

12 minutes

Step-by-step explanation:

added in the picture

P, Q and R are points in the same
horizontal plane. The bearing of
Q from P is 150° and the bearing
of R from Q is 060°.
If |PQ| = 5m and QR = 3m,
Find the bearing of R from P.
correct to the nearest degree./

Answers

Answer: 119°

Step-by-step explanation:

From the positive y-axis, all angles are measured clockwise

PR = PQ + QR = 5[150°] + 3[60°]

X = 5*sin150 + 3*sin60 = 5.1

Y = 5*Cos150 + 3*Cos60 = -2.83

TanA = X/Y

A = -61° = 61° East of South = 119° Clockwise

Therefore, the bearing of R from P is 119°

What is 1/3 of 26 2/3. Please help me

Answers

Answer:

8.888(8)

Step-by-step explanation:

(26 +2/3)/ 1/3 =8.8888888889

A piecewise function is represented by the graph below.

On a coordinate plane, a piecewise function has 2 lines. The first line is made up of 2 lines. One line goes from (negative 5, 3) to (negative 1, negative 1) and then goes up to a closed circle at (1, 1). The second line has an open circle at (1, 2) and then continues up through (3, 4).
What is the domain for the piece of the function represented by f(x) = x + 1?

x < –1
–1 ≤ x ≤ 1
1 ≤ x < 2
x > 1

Answers

Because we have an open circle at (1, 2), and then the line continues up, we conclude that the domain is:

D: x > 1.

What is the domain for the piece of the function represented by f(x) = x + 1?

Here we know that:

"The second line has an open circle at (1, 2)"

This means that the value x = 1 is not on the domain of the second line, and we know that the line "then continues up through (3, 4)"

(notice that these are two points on the line y = x + 1).

So we conclude that x = 1 is the lower bound of the domain of that line (and we can't tell that there is an upper bound).

Then we can just write the domain as:

D: x > 1.

So the last option is the correct one.

If you want to learn more about domains:

https://brainly.com/question/1770447

#SPJ1

What is the length of leg s of the triangle below? 45 √32 45° A. √4 B. 1.5 C. 16 ​

Answers

Answer:

s = 4 units

Step-by-step explanation:

Given is isosceles right triangle, since its interior angles are 45°, 45° and 90°.

The missing length is therefore same as the length of the other leg:

s = 4

Note: This is not included in the answer choices.

Answer:

4 units

Step-by-step explanation:

We can use the converse theorem of the isosceles triangle to find the missing leg.

Converse Isosceles triangle theorem: If two angles are congruent in a triangle, then sides opposite to those angles are also congruent.

Therefore,

As there are two 45° angles, the opposite sides to those are also congruent.

∴ s = 4

Will mark brainliest if you can help!

Answers

Answer:

ln(20) = 2.9957

Here given:

ln(4) = 1.3863

ln(5) = 1.6094

Evaluating with that:

[tex]\rm \Rightarrow ln\left(20\right)=ln\left(5\right)+ln\left(4\right)\\[/tex]

[tex]\rm \Rightarrow ln\left(20\right)=1.3863 \ + \ 1.6094[/tex]

[tex]\rm \Rightarrow ln\left(20\right)=2.9957[/tex]

my dad began paying me an allowance when i was in eighth grade. what is the indirect object?

Answers

Answer:

Step-by-step explanation:

The answer would be "me" as the indirect object

PLEASE HELP ASAP I WILL GIVE BRAINLYEST!!!

Answers

Answer:

Step-by-step explanation:

the numerator goes in side of the radical

The graph of the cube root parent function y = RootIndex 3 StartRoot x EndRoot is translated to form f(x) shown on the graph.

On a coordinate plane, a cube root function goes through (negative 7, 0), has an inflection point at (negative 6, 1), and goes through (2, 3).

Which equation represents f(x)?

f(x) = RootIndex 3 StartRoot x + 6 EndRoot + 1
f(x) = RootIndex 3 StartRoot x minus 6 EndRoot + 1
f(x) = RootIndex 3 StartRoot x + 6 EndRoot minus 1
f(x) = RootIndex 3 StartRoot x minus 6 EndRoot minus 1

Answers

Step-by-step explanation:

The graph of the cube root parent function y = RootIndex 3 StartRoot x EndRoot is translated to form f(x) shown on the graph.

On a coordinate plane, a cube root function goes through (negative 7, 0), has an inflection point at (negative 6, 1), and goes through (2, 3).

Which equation represents f(x)?

f(x) = RootIndex 3 StartRoot x + 6 EndRoot + 1

f(x) = RootIndex 3 StartRoot x minus 6 EndRoot + 1

f(x) = RootIndex 3 StartRoot x + 6 EndRoot minus 1

f(x) = RootIndex 3 StartRoot x minus 6 EndRoot minus 1

Answer:

Step-by-step explanation:

The translation of the parent function is:

g(x) = ∛(x + 6) + 1

How do translations work?

There are two types of translations, these are:

Horizontal translation:

For a function f(x), a horizontal translation of N units is written as:

g(x) = f(x + N)

If N is positive, the translation is to the left.

If N is negative, the translation is to the right.

Vertical translation:

For a function f(x), a vertical translation of N units is written as:

g(x) = f(x) + N

If N is positive the translation is upwards.

If N is negative the translation is downwards.

Here we start with the parent function:

f(x) = ∛x

And we apply two translations such that:

g(x) = ∛(x + a) + b

Such that:

g(-7) = 0

g(2) = 3

Then we have the system of equations:

∛(-7 + a) + b = 0

∛(2 + a) + b = 3

From the options, the only ones that make the first option true are:

g(x) = ∛(x + 6) + 1

Such that when evaluated in x = -7 we get:

g(-7) =  ∛(-7 + 6) + 1 =  ∛(-1) + 1 = 0

When evaluated in x = 2 it gives:

∛(2 + 6) + 1 =  ∛(8) + 1 = 2+ 1 = 3

So the only option that meets these conditions is:

g(x) = ∛(x + 6) + 1

Which is a translation to the left of 6 units and up 1 unit.

If you want to learn more about translations, you can read:

brainly.com/question/17586310

an airplane that is flying at an altitude of 30 000 ft is beginning to descend at a rate of 1000 feet per minute. a helicopter is beginning its trip, starting at an altitude of zero feet. the helicopter ascends more slowly than the airplane, going up at a rate of 500 feet per minute. after how many minutes will the airplane and the helicopter be at the same altitude

Answers

Using linear functions, it is found that the airplane and the helicopter will be at the same altitude after 20 minutes.

What is a linear function?

A linear function is modeled by:

y = mx + b

In which:

m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.b is the y-intercept, which is the value of y when x = 0, and can also be interpreted as the initial value of the function.

The functions that gives the height of the airplane and the helicopter, after t minutes, is given by:

A(t) = 30000 - 1000t.H(t) = 500t.

They will be equal when:

A(t) = H(t).

Hence:

30000 - 1000t = 500t

1500t = 30000

t = 30000/1500

t = 20 minutes.

More can be learned about linear functions at https://brainly.com/question/24808124

#SPJ1

Complete the square to make a perfect square trinomial. Then, write the result as a binomial squared. u2+65u

Answers

Answer:

(u + [tex]\frac{65}{2}[/tex] )²

Step-by-step explanation:

u² + 65u

to complete the square

add ( half the coefficient of the u- term )²

= u² + 2([tex]\frac{65}{2}[/tex] )u + [tex]\frac{4225}{4}[/tex]

= (u + [tex]\frac{65}{2}[/tex] )²

Please help my question is in the attachment!

Answers

Answer:

a = -9

b = -3

c = 11

d = 19

Step-by-step explanation:

a. x = -2

y= + 3x + 1

y= -2²+ 3(-2)+1

y= -4-6+1

y = -9

b. x= -1

y= + 3x+ 1

y= -1² + 3(-1) +1

y= -1 -3 + 1

y = -3

c. x =2

y = + 3x +1

y= 2²+ 3(2) +1

y= 4 +6 +1

y = 11

d. x= 3

y = +3x +1

y = 3² +3(3) +1

y= 9 +9 +1

y = 19

Some children research their classmates' favourite colour. They show the results in a pie chart. 40 children were asked about their favourite colour. How many children chose each colour? red = green = blue =​

Answers

Step-by-step explanation:

Can you attach the questions please? Thanks

g(x)=f(x)-3 which statement best describes the graph of g(x) with the graph of f(x)

Answers

Answer: The graph of g(x) is the graph of f(x) shifted 3 units down.

Other Questions
Find the mean of the following group of numbers: 6. 1, 5. 9, 4. 2, 5. 9, and 10. 7. Round your answer to the nearest tenth 7. Give reason: a. The motion of a bu's starting from a bus station is an example of non- uniform motion. how A truck accelerating at 0.0083 meters/second2 covers a distance of 5.8 104 meters. If the truck's mass is 7,000 kilograms, what is the work done to reach this distance? Answer two questions about system a and b The delegates who came to Philadelphia for the Constitutional Convention had the sameimmediate priorities on what should be considered in the discussions.Select one:O TrueO False Please help me smart peepsDetermine if the two triangles below are similar and state how you know. If you wanted to change by focusing on understanding the viewpoints of others when making decisions, rather than making entirely logic based decisions, which trait should you focus on improving Se the following tax rates, ceiling and maximum taxes: employee and employer oasdi: 6.20% $142,800 $8,853.60 employee* and employer hi: 1.45% no limit no maximum self-employed oasdi: 12.4% $142,800 $17,707.20 self-employed hi: 2.9% no limit no maximum *employee hi: plus an additional 0.9% on wages over $200,000. also applicable to self-employed. rounding rules: unless instructed otherwise compute hourly rate and overtime rates as follows: carry the hourly rate and the overtime rate to 3 decimal places and then round off to 2 decimal places (round the hourly rate to 2 decimal places before multiplying by one and one-half to determine the overtime rate). if the third decimal place is 5 or more, round to the next higher cent. if the third decimal place is less than 5, drop the third decimal place. also, use the minimum hourly wage of $7.25 in solving these problems and all that follow. crow earned $585.15 during the week ended march 1, 20--. prior to payday, crow had cumulative gross earnings of $4,733.20. round your answers to the nearest cent. a. the amount of oasdi taxes to withhold from crow's pay is $fill in the blank 1. b. the amount of hi taxes to withhold from crow's pay is How to translate a graph of y= absolute value of x to obtain the graph of y= absolute value of x-6 cann someone plsss help me The composite figure is made up of a parallelogram and a rectangle. Find thearea. (choices in picture) because research is blank______, it is important to figure out beforehand exactly what problem needs to be solved. Agrowth and development.wateris the last nutrient your body needs and cannot live without for more thardays. The best source is from drinking water or eating fruits and vegetables. Water helps transpootherthroughout the body.balance dietCalories are a measure ofA Food Calorie is the amount ofenergyIron is agives you all the Nutrients you need.6. Minerals come from thebut we don't have to eat Rocks toget them. We can eat plants or the animals that ate the plants to get the minerals we need.7. A Balanced diet means eating aof foods.it takes to heat 1 Liter of water 1 Degreeand you need it for yourand to build Red Blood Cells. The What is necessary to determine the z-score for a raw score in a particular set of scores?. Sunil draws a regular hexagon and a convex quadrilateral on a sheet of paper, so that no side of the quadrilateral lies on the same line as a side of the hexagon. what is the maximum total number of points in which the sides of the quadrilateral can intersect the sides of the hexagon? Read this information from Toms biographical essay about Queen Elizabeth I.One effect of Elizabeths reign was a long period of peace in England.In which part of the essay does this information belong?first paragraph: introductionsecond paragraph: backgroundthird paragraph: impactfourth paragraph: conclusion Triangle abc is represented. points d and f are marked on side ab and points e and g are marked on side ac. segments de and fg are drawn. if , then line segment is parallel to line segment . The graphs below have the same shapes. What is the equation for the red graph? A scientist measures the standard enthalpy change for the following reaction to be -139.5 kj :h2(g) + c2h4(g)c2h6(g)based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of c2h4(g) is _____ kj/mol. what does a equal if 2a=(5/2)(5/4)