Mathematics High School

Which properties justify the steps taken to solve the system? {2a+7b=03a−5b=31 10a+35b=0; 21a−35b=217 ​31a = 217 a = 7 2(7)+7b=0 14 + 7b = 0 7b=−14 b=−2 what are each of the steps taken?

Answers

Answer 1

9514 1404 393

Explanation:

2a+7b=0 . . . . . . . . given [eq1]

3a−5b=31 . . . . . . . .given [eq2]

10a+35b=0 . . . . . . multiplication property of equality 5×[eq1] = [eq3]

21a−35b=217 ​. . . . .multiplication property of equality 7×[eq2] = [eq4]

31a = 217 . . . . . . . . addition/substitution properties of equality [eq3]+[eq4]

a = 7 . . . . . . . . . . . . division property of equality (÷31)

2(7)+7b=0 . . . . . . . .substitution property of equality; a=7 in [eq1]

14 + 7b = 0 . . . . . . . properties of real numbers

7b=−14 . . . . . . . . . . addition property of equality; add -14

b=−2 . . . . . . . . . . . . division property of equality (÷7)

Related Questions

Please please help I will give brainliest

Answers

Answer:

67

4*4*4=64

64+3=

67

THE ANSWER IS 67!!!!!!

Each week, the price of oranges at the farmer's market increases by 20%. The price of oranges this week is 2.50 What was the price last week

Answers

The price last week was $2.08

Answer:4.50

Step-by-step explanation:

The speed limit on a road is 45 mph what is the rate in miles per minute

Answers

The answer is 320 minutes

The rate in miles per minute is 320

PLS helpp
ill give brainliest

Answers

the answer is c. if u make a number line, -2.5 would be less than -2.

Select the correct days. Gina tracks the low temperatures for a city over six days. Identify the days colder than -1.75°F.

Answers

Answer:

[tex]Monday = -2.5F[/tex]

[tex]Tuesday = -1.9F[/tex]

Step-by-step explanation:

Given

See attachment

Required

Days colder than -1.75°F

From the attachment, we have:

[tex]Monday = -2.5F[/tex]

[tex]Tuesday = -1.9F[/tex]

[tex]Wednesday = 0F[/tex]

[tex]Thursday = -1.5F[/tex]

[tex]Friday = 0.5F[/tex]

Days with temperature less than -1.75°F are colder.

-2.5 and -1.9 are less than -1.75

So, we have:

[tex]Monday = -2.5F[/tex]

[tex]Tuesday = -1.9F[/tex]

Answer:

:)

Step-by-step explanation:

uhh- well uh i need help and it would be lovely if ya’ll helped ty very much

Answers

Answer:

x + 3 = y

Step-by-step explanation:

Hope that helps!

x + 3 = y

Try substitute every number with the equation above.

Sub x=-4 and y=-1,
-4 + 3 = -1

-1 = -1


Sub x=-3 and y=0
-3 + 3 = 0

0 = 0


Sub x=-2 and y=1
-2 + 3 = 1

1 = 1


Sub x=-1 and y=2
-1 + 3 = 2

2 = 2


Hope it helps!

A lumberjack needs to climb a tree to place a satellite tower in the tree top in the woods. The satellite signal needs to reach a horizontal distance of 3500 meters along the ground. If the angle of elevation from the farthest distance along the ground that the satellite reaches to the satellite in the tree is 18 degrees, what is the radius of the satellite signal? Round your answer to the nearest meter.

Radius of the satellite signal = meters

Answers

Answer: I use clickcaculators.com ;)

Step-by-step explanation:

does anyone know the answer

Answers

Answer:

y+8x X 5

Step-by-step explanation:

Answer:

first one and last one

Step-by-step explanation:

what is the distance between-2 and -5 on the number line?

Answers

Answer:

3

Step-by-step explanation:

on a number line, we use the absolute values to find the difference.

the absolute value of -2 is 2

the absolute value of -5 is 5

5-2=3

so, the distance between -2 and -5 on a number line is 3

can someone help me how to calculate a square root of 8​

Answers

Answer:

2.82842712475

Step-by-step explanation:

when you square 2.82842712475 your answer is 8 so the number above Is answer

Answer:

8 = 64 √8 = 2.828

Step-by-step explanation:

√8 = √(4 * 2) = √4 * √2 = 2√2 ≈ 2.828427.

Hope this helps you!

A ball falls from the top of a building. When it strikes the ground its velocity is 10 m/s. It took 5 seconds to fall. What is its acceleration? _____ m/s2

Answers

Answer:

a = 2 m/s²

Step-by-step explanation:

[tex]a = \frac{v-u}{t}[/tex]

where v is the final velocity, u is the initial velocity, and t is the time it takes. the intial velocity is always 0 m/s. given the equation, we subsitute:

[tex]a = \frac{10m/s - 0 m/s}{5s}[/tex]

a = 10m/s ÷ 5s

a = 2 m/s²

A set of 25 two digit numbers are listed below 10,17,20,23,24,28,32,39,42,25,26,52,55,58,61,65,66,72,75,78,79,85,94,97,98. What is the probability of the sum of the number's digits is odd?

Answers

Answer:

0.48

Step-by-step explanation:

Given the data:

X:

10,17,20,23,24,28,32,39,42,25,26,52,55,58,61,65,66,72,75,78,79,85,94,97,98

Sum of each of the numbers :

1, 8, 2, 5, 6, 10, 6, 12, 6, 7, 8, 7, 20, 13, 7, 11, 12, 9, 12, 15, 16, 13, 13, 16, 17

Probability that sum of the number's digit is odd:

Number of odd sum / total numbers

Number of odd sum = 12

Total numbers = 25

12 / 25

= 0.48

calculate the Unknown Missing angle measures ​

Answers

Answer:

Step-by-step explanation:

c=180-123=57

b=180-123=57

d=180-57-55=68

a=180-68-57=55

a,b,c,d=55, 57, 57, 68 degrees

What is 2/10, 2/5, and 2/20 ordered form least to greatest?

Answers

Step-by-step explanation:

2/20, 2/10 , 2/5

set them all to the same denominator of 20:

2/20, ,4/20, 8/20

Solve by factoring: x2 – 9x + 20 = 0

A. x = - 4 and x = - 5

B. x = 4 and x = 5

C. x = 20 and x = - 9

D. x = - 4 and x = 5

Show your work​

Answers

Answer:

Answer

Given equation is:

x

2

−9x+20=0

⇒x

2

−5x−4x+20=0

⇒(x−4)(x−5)=0

⇒x=4andx=5

Answer:
B.x = 4 x=5

Expiation:
x * (x-4)-5(x-4)=0
(x-4)*(x-5)=0
x-4=0
x-5=0
x1= 4 x2= 5

What is the slope of the line that passes through the points (-1,-10) and (-1,-2)?

Answers

Answer:

Infinite; no slope

Step-by-step explanation:

Because both points have -1 as X they are both located on the same line

This gives them no slope

Solve the missing angle measurement

Answers

You just have to subtract everything from 360. So it would be like this

360 - 105 - 80 - 75= the number you get

Jus Plug that into a calculator and you have your answer :)

Can someone help me find the area of this ? If you can thank you so much , it's been awhile since I've done it ​

Answers

Answer:

185

Step-by-step explanation:

Hope this helps

Can you all help? Giving brainliest to whoever can help me!

Answers

Answer:

x=11

Step-by-step explanation:

15x+15=180      they are supplementary angles to each other so their sum is

                        equal to 180 degrees.

subtract 15 from both sides

15x=165

divide each side by 15

x=11

Solve the inequality.
20 + 8.1 > 28

Answers

Answer:

You can't solve since there is no variables

The inequality from the question is true

Question:
What are the solutions to 3x^2 + 12x + 6 = 0?

Hint::
use the quadratic formula

Answers

Answer:

     x₁ = - 2 + √2 ,   x₂ = - 2 - √2

Step-by-step explanation:

[tex]3x^2 + 12x + 6 = 0\\\\a=3\,,\ b=12\,,\ c=6\\\\\\ x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}\\\\ x=\dfrac{-12\pm\sqrt{12^2-4\cdot3\cdot6}}{2\cdot3}=\dfrac{-12\pm\sqrt{144-72}}{2\cdot3}=\dfrac{-12\pm\sqrt{72}}{2\cdot3}=\dfrac{-12\pm6\sqrt{2}}{6}\\\\x_1=\dfrac{6(-2+\sqrt{2})}{6}=-2+\sqrt2\\\\x_2=\dfrac{6(-2-\sqrt{2})}{6}=-2-\sqrt2[/tex]

Jaxon invested $960 in an account paying an interest rate of 6.1% compounded monthly. Assuming no deposits or withdrawals are made, how long would it take, to the nearest year, for the value of the account to reach $1,720

Answers

Answer: 10 years

Step-by-step explanation:

1720=960(1+0.061/12)

A light bulb manufacturer claims that the lifetime of the bulbs is normally distributed with a mean of 5000 hours and a standard deviation of 250 hours. If 20000 bulbs are produced on a particular day, what percentage of the bulbs will have a lifetime of between 4750 and 5500 hours?

Answers

Answer:

88

Step-by-step explanation:

Mia got $80 for her birthday and spent $60. What percent of her birthday money does she have left

Answers

Answer:

16 percent is left

Step-by-step explanation:

20/100×80

Hope it helps!!

Pls, answer fast with an explanation. At a carnival, it costs $138.00 for 92 tickets. Write an equation that can be used to find the total cost (c) for any number of tickets (t) you buy.

Answers

92 tickets = $138
138/92 = 1.5
1 ticket = $1.50
1.5t = c

Some steps are on paper

ANSWER ASAP THEIRS A SCREEN SHOT TO HELP SHOW
AND TELL WHY PLEASE

Answers

b d and f it is getting larger, 3*2 is 6 meaning the scale factor is two, and point o is the vertex i think

I need help with this question. I need to find the perimeter of the hexagon RSTUVW.​

Answers

9514 1404 393

Answer:

  47.71

Step-by-step explanation:

Two "special" triangles are involved.

ΔSWR is a 30°-60°-90° right triangle, so will have sides in the ratio 1 : √3 : 2.

ΔUVW is a 45°-45°-90° right triangle so will have sides in the ratio 1 : 1 : √2.

For ΔSWR, the side SW is given as 6, so the other sides are ...

  WR = 6√3

  RS = 2(6) = 12

For ΔUVW, the side WU is given as 8, so the other sides are ...

  UV = VW = 8/√2 = 4√2

Then the perimeter of the figure is ...

  P = RS +ST +TU +UV +VW +WR

  P = 12 +8 +6 +4√2 +4√2 +6√3 ≈ 47.71

what is the area of a square yards of a rectangle with a length of 9 yds and a width of 4 yds?

Answers

[tex]a = lw[/tex]

[tex]a = (9)(4)[/tex]

[tex]a = 36 \: {yds}^{2} [/tex]

Answer:

Here we can understand that the shape is a rectangle as length is not equal to width.

Area of the rectangle in square yards when length is 9 yds and width is 4 yds will be,

Area of Rectangle = LENGTH × WIDTH

⇒ 9*4

⇒ 36 sd yds

Thus the are will be  36 sd yds

A new car is purchased for 24800 dollars. The value of the car depreciates at 12% per year. What is the y-intercept (starting value)? *

Answers

Answer:

$24,800

Step-by-step explanation:

that's how much the car costs at year 0

Answer:

Step-by-step explanation:

The starting value, y intercept, is just the initial value as it has not depreciated when time or x is zero.

The equation described is y=24800(0.88)^x

Find the area of the circle 18in

Answers

1017.88in^2

You need to use pi

Answer:

1017.88inches^2

Step-by-step explanation:

Area of a circle=pi * radius^2

324*pi=1017.88

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