SOL Practice After Variation Summative
1. If y varies directly as x, what is the equation for the direct variation shown in the table
below?
x
-2
-1
0
1
2
y
-14 -7
0
7
14
1
A. y = 7x
B. y = 7x
7
C. y = 𝑥
D. 7y = x
2. An experiment is conducted on a container of gas that is kept at a constant
temperature.




When the pressure on the gas is 30 pounds per square inch, the volume is 120
cubic inches.
When the pressure on the gas is 40 pounds per square inch, the volume is 90
cubic inches.
Let p represent the pressure on the gas.
Let v represent the volume of the gas.
Which statement is true about this relationship?
A.
B.
C.
D.
The volume of the gas varies directly with the pressure because v = 4p.
The volume of the gas varies directly with the pressure because vp = 3,600.
The volume of the gas varies inversely with the pressure because v = 4p.
The volume of the gas varies inversely with the pressure because vp = 3,600.
2
3. The cost of fabric varies directly with the amount of fabric purchased. If 1 3 yards of
1
fabric cost $10.00, how much would 4 2 yards cost?
$
4. A repairman estimated the cost of replacing a part in Mrs. James’ computer would be
at most $225. The estimate included $35 for the part, a $40 service charge, and $30
per hour for labor. What is the maximum number of hours the repairman estimated
for the job?
A.
B.
C.
D.
1
42
5
1
52
6
5.
The miles per gallon, m, of an experimental car is given by
𝑠
2
m = 75 – 0.3( )
10
where s is the car’s speed in miles per hour. What is the car’s miles per gallon
when its speed is 100 miles per hour?
A.
B.
C.
D.
10 mpg
30 mpg
45 mpg
50 mpg
6. Which of the following represents an inverse variation? Circle all that apply.
x
0.25
1
1.5
2
3
y
96
24
16
12
8
−4
y = -4x
y=
xy = -4
y = −4
𝑥
𝑥
x
0
1
2
4
6
y
0
0.25
0.5
1
1.5
3
7. For a given function, y varies directly as x. The constant of variation is . Plot three
2
points that could lie on the graph of this function.
8. What is the slope of the equation 2𝑦 + 3𝑥 = −8 ?
A. 3
3
B. 2
−3
C. 2
D. −3