test review: direct variation. rewrite the direct variation equation, y = kx, in terms of “k.”...
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Test Review:
Direct Variation
Rewrite the direct variation equation, y = kx, in terms of “k.” In other words, k = _________.
Test Review: Direct Variation
Solve for x:
42 7
9x
Test Review: Direct Variation
Using y = 7x, what is the value of x if y = 56?
Test Review: Direct Variation
Test Review: Direct Variation
Referring to the table below, use a proportion to predict Michael’s numerical grade on Test #3.
Test # Hours Studied
Test Grade
1 1.5 75
2 2 100
3 1.2
If y varies directly as x, and y = 68 when x = 4, find x when y = 51.
Test Review: Direct Variation
Complete the following table for y = 1
4x.
XY
0
1
2
3
4
Graph the table of values
Test Review: Direct Variation
504540353025201510
5
A T-shirt cost $3.00. Draw a graph to represent how much 4, 6, 8, and 10 T-shirts would cost.
What is the constant of proportionality (k)?____
Test Review: Direct Variation
Test Review: Direct Variation
x 0 1 2 3 4
y
Complete the following table for y = 3x
Write a proportion to show how you would solve the problem - do not solve:A rose bush grows 4 inches every 3 months. How many inches will the bush grow in 1 year (1 year equals 12 months)?
Test Review: Direct Variation
Suzy can walk 1 mile in 8 minutes. Create a table of values that represent time and distance.
Distance (x)Time (y)
0
3
6
9
What direct variation equation would represent the miles and time that Suzy can walk?________
Test Review: Direct Variation
What value of n makes the equations true?
24 6
11n
Test Review: Direct Variation
Which of the given values satisfies the equation y = 6x
A.x = 7, y = 42 B. x =4, y = 2
C. x =3, y = 24 D. x = 1.5, y = 5.5
Test Review: Direct Variation
The variables x and y vary directly. When x = 13, y = 39. What equation relates x and y?
Test Review: Direct Variation
Test Review: Direct Variation
a. Using y = 2x, create a table in which x = 0, 1, 2, 3b. Plot these points on the graph below
Johnny scores 24 points in three basketball games. The season has 8 games. How many points can Johnny expect to score by the end of the season?
Test Review: Direct Variation
Complete the following table for y = 4.5x
x0 1 2 3 4
y 0 4.5 9 ? 18
Test Review: Direct Variation
The graph below shows the cost of gasoline per gallon. What is the equation for graph?
Test Review: Direct Variation
If y varies directly with x, and y = 6 when x = 8, find x when y = 24.
Test Review: Direct Variation
Which of the following equations is a direct variation?
A. y + 15 = x B. x - 2 = y
C. 3x = y D. xy = 7
Test Review: Direct Variation
Five packs of gum cost $3.00. At that rate, about how much will 36 packs of gum cost?
Test Review: Direct Variation
In a direct variation, as the quantity of video games you purchase decreases, what happens to the total cost (your bill) of the video games?
Test Review: Direct Variation
Which of the following tables represent a direct variation?A. B. C. D.
x y
3 12
6 24
9 36
12 48
x y
1 2
2 3
3 4
4 5
x y
24 1
12 2
8 3
6 4
x y
2 5
6 9
10 13
14 17
Test Review: Direct Variation
Which graph represents an direct proportion?
a. b.
c. d.
Test Review: Direct Variation
y varies directly with x. If y = 8 and x = 4, what does y equal when x=3?
Test Review: Direct Variation
Write the direct variation equation for the following table. _________
x y
4 1
8 2
12 3
16 4
Test Review: Direct Variation