Answer:
Average speed of boat = 3.67 km/h
Average speed of stream = 0.63 km/h
Step-by-step explanation:
30 km upstream in 10 hours gives a speed of 30/10 = 3 km/h relative speed of boat and stream
Same way, 44 km in 10 hrs = 4.4 km/h relative speed of boat and stream.
Let the speed of the stream be y
Let the speed of both be x, then
x - y = 3.... (1)
x + y = 4.4.... (2)
Subtract 1 from 2
2y = 1.4
y = 1.4/2 = 0.7 km/h
substitute value of y in 1
x - 0.7 = 3
x = 3.7 km/h
Also, 40 km upstream in 13 hrs gives speed of 3.08 km/h
55 km in 13 hrs gives 4.2 km/h
Let speed of boat be x and that of stream be y
x - y = 3.08.... (1)
x + y = 4.2..... (2)
Subtract 1 from 2
2y = 1. 12
y = 0.56 km/h
Substitute value of y in 1
x - 0.56 = 3.08
x = 3.64 km/h
Average speed of boat = (3.7 + 3.64)/2
= 3.67 km/h.
Average speed of stream = (0.7 + 0.56)/2 = 0.63 km/h
Answer:
Let the speed of boat in stream be x km/hrAnd the speed of boat in still water be y km/hr.For upstream = x - yFor downstream = x + yAs we know that,
[tex]\bigstar \: \: \sf Time = \dfrac{Distance}{Speed} \\ \\ [/tex]
[tex]\bigstar\:\underline{\boldsymbol{According\: to \:the\: Question\:now :}} \\[tex]
[tex]:\implies \sf \dfrac{30}{x - y} + \dfrac{44}{x + y} = 10 \\ \\ \\ [/tex]
[tex]:\implies \sf \dfrac{40}{x - y} + \dfrac{55}{x + y} = 13 \\ \\ \\[/tex]
[tex]\sf Let \: \dfrac{1}{x - y} = \textsf{\textbf{m}} \sf \: \: and \: \: \sf{\dfrac{1}{x + y} = \textsf{\textbf{n} }}\\ \\ \\[/tex]
[tex]:\implies \sf 30m + 44n = 10\: \: \: \: \Bigg\lgroup \textsf{\textbf{Equation (i)}}\Bigg\rgroup \\ \\ \\[/tex]
[tex]:\implies \sf 40m + 55n = 13\: \: \: \: \Bigg\lgroup \textsf{\textbf{Equation (ii)}}\Bigg\rgroup \\ \\ \\[/tex]
[tex]\qquad\tiny \underline{\frak{ Multiply \: equation \: (ii) \: by \: 3 \: and \: equation \: (i) \: by \: 4 :}} \\[/tex]
[tex]:\implies \sf 120m + 176n = 40\: \: \: \: \Bigg\lgroup \textsf{\textbf{Equation (iii)}}\Bigg\rgroup \\ \\ \\[/tex]
[tex]:\implies \sf 120m + 165n = 39\: \: \: \: \Bigg\lgroup \textsf{\textbf{Equation (iv)}}\Bigg\rgroup \\ \\ \\[/tex]
[tex]\qquad\tiny \underline{\frak{ Substracting \: equation \: (iii) \: from \: equation \: (iv) \: we \: get :}} \\[/tex]
[tex]\sf 120m + 176n = 40 \\ \\
\sf 120m + 165n = 39 \\ \\ [/tex]
[tex]\sf \: \: ( - ) \:\:\: \: \: ( - ) \: \: \: \: \: \: \: ( - ) [/tex]
_____________________
[tex]\: \: \: \: \qquad\sf 11n= 1 \\[/tex]
[tex]\: \: \: \: \: \qquad\sf n= \dfrac{1}{11} \\ \\ [/tex]
[tex]\qquad\tiny {\frak{ Put\: n = \dfrac{1}{11}\:in\:equation \: (i) \: we \: get :}} \\[/tex]
[tex]\dashrightarrow\:\:\sf 30m + 44 \times \dfrac{1}{11} = 10 \\ \\ \\[/tex]
[tex]\dashrightarrow\:\:\sf 30m= 10 - 4 \\ \\ \\[/tex]
[tex]\dashrightarrow\:\:\sf 30m= 6 \\ \\ \\[/tex]
[tex]\dashrightarrow\:\:\sf m= \dfrac{6}{30} \\ \\ \\ [/tex]
[tex]\dashrightarrow\:\:\sf m= \dfrac{1}{5} \\ \\ \\[/tex]
____________________....[tex]\dashrightarrow\:\:\sf \dfrac{1}{x - y} = m\\ \\ \\[/tex]
[tex]\dashrightarrow\:\:\sf x - y= 5\: \: \: \: \Bigg\lgroup \textsf{\textbf{Equation (v)}}\Bigg\rgroup \\ \\ \\[/tex]
[tex]\dashrightarrow\:\:\sf \dfrac{1}{x + y} = n\\ \\ \\[/tex]
[tex]\dashrightarrow\:\:\sf x + y= 11\: \: \: \: \Bigg\lgroup \textsf{\textbf{Equation (vi)}}\Bigg\rgroup \\ \\ \\[/tex]
[tex]\qquad\tiny {\frak{Adding\:equation \: (v) \: and \: equation \: (vi) \: we \: get :}} \\[/tex]
[tex]:\implies \sf 2x = 16 \\ \\ \\[/tex]
[tex]:\implies \underline{ \boxed{ \textsf {\textbf{x = 8 km/hr}}}} \\ \\[/tex]
[tex]\qquad\tiny {\frak{Putting\:x = 8\: in \: equation \: (v) \: we \: get :}} \\[/tex]
[tex]:\implies \sf 8 - y = 5 \\ \\ \\ [/tex]
[tex]:\implies \sf y = 8 - 5 \\ \\ \\[/tex]
[tex]:\implies \underline{ \boxed{ \textsf {\textbf{y = 3 km/hr}}}} \\ \\[/tex]
_________________....[tex]\bigstar\:\underline{\sf{Therefore\: speed\: of \:boat\: in\: still \:water\: and\: speed\: of\: stream:}} \\[/tex]
[tex]\bullet\:\:\textsf{Speed of boat in stream = \textbf{8 km/hr}}\\[/tex]
[tex]\bullet\:\:\textsf{Speed of boat in still water = \textbf{3 km/hr}}\\[/tex]
ill mark u brainliest please help me!
Answer:
C
Step-by-step explanation:
Line AC is equal to line DF.
Answer: The answer is C
Step-by-step explanation:
The way it is written is very important
it goes
AB is to DE
BC is to EF
AC is to DF
What is the solution to this system of linear equations?
7x – 2y = –6
8x + y = 3
(–6, 3)
(0, 3)
(1, –5)
(15, –1)
Answer:
de correct one is
x 0
y 3
hope u got it
Please please help me I’ve attached the question and I’m very confused
Answer:
y = 1/4 x -3
Step-by-step explanation:
The y intercept ( or where it crosses the y axis ) is -3
Pick 2 points to find the slope
(0,-3) and (4,-2)
The slope is
m = (y2-y1)/(x2-x1)
= (-2 --3)/ (4-0)
= (-2+3)/4
1/4
The slope intercept form of the equation is
y = mx+b where m is the slope and b is the y intercept
y = 1/4 x -3
Write a polynomial function of least degree with zeros 1, -2, -3
Answer:
f(x) = (x - 1)(x + 2)(x + 3)
Step-by-step explanation:
The function would be f(x) = (x - 1)(x + 2)(x + 3). This is of the third degree.
Ix
Which expression is equivalent to 6-(-8)?
-6+8
-6+(-8)
6+(-8)
6 + 8
Answer:
6 + 8
Step-by-step explanation:
6-(-8)= 6+8
XYZ is an isosceles triangle inscribed I a circle, center O. XY=XZ= 20 and YZ=18. Calculate to 3.s.f.
a) the altitude of ∆XYZ
b) the diameter of the circle
Answer: 17.9
Step-by-step explanation:
Using Heron's formula:
Area of a triangle is given by:
√s(s-a)(s-b)(s-c)
Where a, b and c ara sides of the triangle and
S = (a+b+c) / 2
In the question above sides are :
XY=XZ= 20 and YZ=18
S = (20 + 20 + 18) / 2 = 58/2 = 29
Area = √29(29-20)(29-20)(29-18)
Area = √29(9)(9)(11)
Area = √25839
Area = 160.74513
Altitude = height(h)
Area = 0.5 × base × height
Base = yz = 18
160.74513 = 0.5 × 18 × h
160.74513 = 9 × h
h = 160.74513 / 9
h = 17.9 (3 s.f)
what is 100,000 written as a power with a base of 10? ANSWER QUICK
Answer:
Its either 10 to the power of 6 or ten to the power of 5
Step-by-step explanation:
...
Which is a true statement about the diagram?
The right answer is of option C.
hope it helps..
good luck on your assignment
Answer:
c
Step-by-step explanation:
Find the value of x.
Answer:
x = -7
Step-by-step explanation:
Make an equation:
3x + 33 = 12
3x = -21
x = -7
Answer:
x = -7
Step-by-step explanation:
form an equation.
14 + x + 2x + 19 = 12
like terms together;
x + 2x = 12 - 14 - 19
simplify;
3x = -21
divide both sides by 3;
x = -7
The length of a rectangle is 20 units more than its width. The area of the rectangle is x4−100.
Which expression represents the width of the rectangle?
1. x2−10 because the area expression can be rewritten as (x2−10)(x2+10) which equals (x2−10)((x2−10)+20).
2. x2+10 because the area expression can be rewritten as (x2+10)(x2−10) which equals (x2+10)((x2+10)−20).
3. x2−30 because the area expression can be rewritten as (x2+10)(x2−10) which equals (x2+10)((x2−30)+20).
4. x2+30 because the area expression can be rewritten as (x2−10)(x2+10) which equals (x2−10)((x2+30)−20).
Answer:
[tex]1. x^2-10[/tex] because the area expression can be rewritten as [tex](x^2-10)(x^2+10)[/tex]which equals [tex](x^2-10)((x^2-10)+20).[/tex]
Step-by-step explanation:
Area of the rectangle [tex]=(x^4-100)[/tex]
[tex]x^4-100=(x^2)^2-10^2\\$Applying difference of two squares: a^2-b^2=(a-b)(a+b)\\(x^2)^2-10^2=(x^2-10)(x^2+10)[/tex]
Since the length of a rectangle is 20 units more than its width.
[tex]Width: x^2-10\\Length=x^2+10=x^2-10+20[/tex]
The correct option is therefore 1.
Answer:
x2−10 because the area expression can be rewritten as (x2−10)(x2+10) which equals (x2−10)((x2−10)+20).Step-by-step explanation:
The area of the rectangle is [tex]x^{4} -100[/tex], which can be factored as [tex](x^{2} +10)(x^{2} -10)[/tex], because it's the difference of two perfect squares.
But, we know that [tex]l=20+w[/tex], where [tex]l[/tex] is the length and [tex]w[/tex] is the width.
Additionally, [tex]l=x^{2} -10+20[/tex] and [tex]w=x^{2} -10[/tex], which means [tex]l=x^{2} +10[/tex].
Therefore, the right answer is A.
What is the equation of the translated function, g(x), if
f(x) = x??
Answer:
There is not enough information to solve. We need some more information to solve this question. The best we can do is
g(x) = g(f(x))
Bus leaves 9:30a.m.The journey takes 26h 20 min. What time will they arrive
Answer:
They will arrive at 11:50 am the next day
Step-by-step explanation: 24 hours is a day so add 2 hours and 20 minutes
Answer:
11:50 a.m.
Step-by-step explanation:
Jeff needs to rent a car for one day, so he shops around to find a car rental company with the lowest overall price. He finds a national rental car company that charges a 12$ daily fee plus .30 per mile, he also find a rental car company that charges a 10$ daily fee, plus a .40 per mile under what conditions would it be less expensive to rent from the national car company?
Answer:
When Jeff travels more than 20 miles
Step-by-step explanation:
Let 'x' be the number of miles traveled by Jeff.
In order for the national car company to be less expensive, then the following condition must be met:
[tex]12+0.30x < 10+0.40x\\12-10 < 0.4x-0.3 x\\2 <0.1x\\20<x[/tex]
This means that when Jeff travels more than 20 miles, it is cheaper to rent from the national car company.
A project cost at $160 and add 20% VAT, How much does it change the job?
Answer: 192
Step-by-step explanation:
160 + (20% × 160) =
160 + 20% × 160 =
(1 + 20%) × 160 =
(100% + 20%) × 160 =
120% × 160 =
120 ÷ 100 × 160 =
120 × 160 ÷ 100 =
19,200 ÷ 100 =
Welcomeeee
A baker needs a total of cups of flour to make four batches of cookies. How much flour, in cups, does she need for each batch of cookies? Write and solve an equation to find the answer.
Answer:
She needs cups of flour for each batch of cookies.
Step-by-step explanation:
Step-by-step explanation:
A baker needs a total cups of flour to make four batches of cookies.
We have to calculate how much flour she needs for each batch of cookies.
Let the flour needed for one batch be f, so the expression would be
f × 4 =
First we convert mixed fraction to proper fraction.
f × 4 =
f =
= × =
Now we convert this proper fraction to mixed fraction.
=
She needs cups of flour for each batch of cookies.
Answer:
she needs 3 1/3 of a cup
Step-by-step explanation:
I have finished the test
EDGE 2021
PLEASE HELP WILL MARK BRAINLIEST
There are 5 boys in a class of 12 students. (a) What is the ratio of all students in the class to girls? (b) What is the ratio of girls to boys?
Answer:
(a) 12:5
(b)12:7
Step-by-step explanation:
HOPE i helped!
The polynomial f(x) is written in factored form: f(x) = (x − 3)(x + 8)(x − 11) What are the zeros of the polynomial function?
x = 3, x = 8, x = 11
x = 3, x = −8, x = 11
x = −3, x = 8, x = −11
x = −3, x = 3, x = −8, x = 8, x = −11, x = 11
Answer:
x=3 x = -8 x = 11
Step-by-step explanation:
f(x) = (x − 3)(x + 8)(x − 11)
Using the zero product property
0 = (x − 3)(x + 8)(x − 11)
0 = x-3 0 = x+8 0 = x-11
x=3 x = -8 x = 11
Answer:
x=3 x = -8 x = 11
Hope this helps!
solve the equation
7h-5(3h-8) = 72
Answer:
h = -4
Step-by-step explanation:
7h-5(3h-8) = 72
Distribute
7h - 15h +40 = 72
Combine like terms
-8h +40 = 72
Subtract 40 from each side
-8h+40-40 = 72-40
-8h = 32
Divide each side by -8
-8h/-8 = -32/-8
h = -4
Steps:
Step 1: Simplify both sides of the equation.
7h−5(3h−8)=72
7h+(−5)(3h)+(−5)(−8)=72(Distribute)
7h+−15h+40=72
(7h+−15h)+(40)=72(Combine Like Terms)
−8h+40=72 −8h+40=72
Step 2: Subtract 40 from both sides.
−8h+40−40=72−40
−8h=32
Step 3: Divide both sides by -8
Answer: h=−4
The answer for this question is h=-4
Please mark me brainliest
Hope this helps.
The triangles are congruent by SSS and HL. Triangles R S T and V W X are shown. Triangle R S T can be rotated about point S and then shifted down and to the left to form triangle V W X. Which transformation(s) can be used to map △RST onto △VWX? reflection only translation only reflection, then translation rotation, then translation
Answer:
rotation then translation
Based on the information given regarding the triangle, the transformations that can be used to map △RST onto △VWX is D. rotation, then translation.
What is a congruent triangle?It should be noted that a congruent triangle simply means when two triangles have the same sides and the same angles.
Since Triangle RST can be rotated about point S and then shifted down and to the left to form triangle VWX, the transformations that can be used to map △RST onto △VWX is rotation, then translation.
Learn more about triangles on:
https://brainly.com/question/2644832
What is the square root of 9?
Answer:
±3
Step-by-step explanation:
sqrt(9)
3*3 = 9
-3*-3 = 9
sqrt(9) = ±3
6x^3-x^2 +17 = 2x^2 + 47
Answer:
Solve the rational equation by combining expressions and isolating the variable x
.
x≈1.89393154
Step-by-step explanation:
please mark brainly
Pls help me with this question I’m trying to Anwser
Answer:Wish i could help, but I'm just as confused.
Step-by-step explanation:
A gardener made a scale drawing of a lawn with a scale factor of 1:10. The
dimensions of her drawing are 7 inches long by 3 inches wide. Her partner plans
to make another scale drawing of the lawn, but with a scale factor of 1:2.
What are the dimensions of her scale drawing?
5 of 16 QUESTIONS
The length is 0.6 inch and the width is 1.4 inches.
The length is 15 inches and the width is 35 inches.
The length is 35 inches and the width is 15 inches.
The length is 1.4 inches and the width is 0.6 inch
SUB
Answer:
The length is 35 inches and the width is 15 inches.
Step-by-step explanation:
First work of the real length of the field. Given is the ratio of drawing to original and the dimensions of the drawing. so in real life the lawn measures 70 inches in length and 30 inches in width.
Now, we have to divide this in the ratio 1:2, which gives
The length of 35 inches and the width of 15 inches.
Hope this helps
Answer:
Your answer is 3 or C.. 35 inches and width of 15 :)
Step-by-step explanation:
Simplify the expression 3x(2x2).
O A.
5x²
OB.
m
5
OC.
m
OD.
6x6
Answer:
6 x^3
Step-by-step explanation:
3x(2x^2).
3*2 = 6
x * x^2 = x^3
6 x^3
if one score of 39 is changed to 40, how will the histogram change?
Answer: Histogram of 30-40 becomes slightly low and histogram of 40-50 becomes slightly high.
Step-by-step explanation:
Since we have given that
C.I. Frequency
10-20 1
20-30 4
30-40 15
40-50 14
If one score of 39 changed to 40.
Then it comes under class interval of 40-50
so, frequency under 30-40 becomes 14.
frequency under 40-50 becomes 15.
So, Histogram of 30-40 becomes slightly low and histogram of 40-50 becomes slightly high.
Answer:
uhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh sorry needed the points lol
y = f(x) = 2x
Find f(x) when x = 1.
Enter the correct answer.
000
I
DONE
Clear all
000
E?
Answer:
2
Step-by-step explanation:
f(x) = 2x
Let x =1
f(1) = 2*1
f(1) = 2
Answer:
f(1)=2
Step-by-step explanation:
We are given the equation:
f(x)=2x
We also know that x=1. Therefore, we can substitute 1 in for every x.
f(1)= 2(1)
Multiply 2 and 1
f(1)=2
f(x) when x=1 is 2.
in a bacterial cell where would you find the DNA plasmids?
Step-by-step explanation:
bacteria also have small, closed-circle of DNA called plasma and present in their cytoplasm .
A store gives away gift bags during a sale. Of these gift bags, 50% are green, 20% are yellow, and 30% are blue. The average number of items in each green bag is 8. The average number of items in each yellow bag is 5. The average number of items in each blue bag is 8. What is the average number of items in all the gift bags? PLS, HELP WILL GIVE YOU 95 PTS!!!!!!!!
Answer:
7
Step-by-step explanation:
So I started with an equation (g for green variable, y for yellow variable, b for blue variable)
8g + 5y + 8b = ??
Because of the lack of variables, I'm not really sure how to tie in the 50%, 20%, and 30%. (It could be unnecessary information)
But going off the average number of items, you have 8 green, 5 yellow, and 8 blue. So you can add them together for 21. From here, you divide 21 by 3 to get your average, 7.
Answer:hmm
Step-by-step explanation:
the graph shows the speed of a vehicle during the final 50 seconds of a journey at the start of the 50 seconds the speed is k metres per second
Answer:
a) 27 m/s
b) 30 m/s
c) i) 3
ii) Deceleration
Step-by-step explanation:
The question is not complete, the correct question is given as:
The graph shows information about the speed of a vehicle during the final 50 seconds of a journey. At the start of the 50 seconds the speed is k metres per second. The distance travelled during the 50 seconds is 1.35 kilometres.
(a) Work out the average speed of the vehicle during the 50 seconds
(b) Work out the value of k.
(c) (i) Calculate the gradient of the graph in the final 10 seconds of the journey
(ii) Describe what this gradient represents
Answer:
The graph is attached. The total time = 50 seconds, total distance = 1.35 km = 1350 m
a) The average speed is the ratio of the total distance traveled to the total time taken to cover this distance. The average speed is given by the formula:
[tex]Average \ speed=\frac{total\ distance}{total\ time}\\ Substituting: \\ Average \ speed=\frac{1350\ m}{50\ s} = 27\ m/s[/tex]
b) From the graph, the total distance covered is the area of the graph. The graph is made up of a rectangle and triangle, the area of the graph is equal to the sum of area of rectangle and area of triangle.
[tex]Total \ distance=Total\ area=Area\ of \ rectangle+Area\ of \ triangle\\Total \ distance=(length *breadth)+\frac{1}{2}base*height\\1350 \ m=(40*k)+0.5*10*k\\1350=40k+5k\\45k=1350\\k=1350/45\\k=30\ m/s[/tex]c) i) The gradient in the last 10 seconds is the ratio of change in speed to change in time
[tex]Gradient=\frac{change\ in\ speed }{change\ in\ time}=\frac{0-k}{50-40} \\ bt \ k=30\\Gradient=\frac{0-30}{50-40}= \frac{-30}{10} =-3[/tex]
ii) Since the gradient is negative it means it is deceleration. That is in the in the last 10 seconds the vehicle decelerates at a rate of 3 m/s²
Answer:
Step-by-step explanation:
a)34 m/s
b) 40k=34
k=34/40
k=0.85 m/s
Help me please…………………………
Answer:
Correct option: First one -> [tex]x^2 = -12y[/tex]
Step-by-step explanation:
The focus and the vertex have the same x-coordinate, so we have a vertical parabola. The standard equation for this parabola is:
[tex]y = a(x-h)^2 + k[/tex]
If the vertex is at the origin, we have that:
[tex](h, k) = (0,0)\\h = 0, k = 0[/tex]
If the focus is at (0,-3), we have that:
[tex](h, k+p) = (0, -3)[/tex]
[tex]p = 1/4a[/tex]
[tex]k + p = -3[/tex]
[tex]1/4a = -3[/tex]
[tex]a = -1/12[/tex]
So we equation of the parabola is:
[tex]y = -x^2/12[/tex]
[tex]x^2 = -12y[/tex]
Correct option: First one
