Direct and Inverse Variations Review
1.
List 3 differences between direct and inverse variations.
a. ________________________________________________________________________
b. ________________________________________________________________________
c. ________________________________________________________________________
2. Label each table as direct, inverse, or neither. If it is direct or inverse, write an equation for the variation.
x
y
x
y
x
y
4
9
3
36
5
10
12
3
2.5
30
7
13
2
18
2
24
9
21
0.5
72
1.5
18
11
32
3.
Each set of ordered pairs is a direct variation. Find the missing value.
a. (3, 2) and (6, y)
b. (3, y) and (9, 15)
c. (2.5, 5) and (x, 9)
4.
Each set of ordered pairs is an inverse variation. Find the missing value.
a. (5, 8) and (4, y)
b. (3, 18) and (x, 27)
c. (12.4, 6.6) and (x, 8.8)
5. Is each situation a direct or inverse variation?
a. The cost of a $50 birthday gift is split among friends.
b. You purchase some peaches at $1.29 per pound.
6.
The distance traveled on a trip at a constant rate varies directly with the time traveled. If the rate is 65 mph,
how long will it take to travel 330 miles? Write a direct variation equation to represent this situation.
7.
2 men can paint a house in 3 days. How long will it take if 5 men paint the house? Give you r answer as a
mixed number. Write an inverse variation to represent this situation.
8.
Sally can ride to school in 15 minutes at 12 miles per hour. Her older brother Stanley can ride the same distance
to school in 9 minutes. How fast does Stanley ride? Write an inverse variation equation to represent this
situation.
9. Graph the direct variation y = -2x.
How is this different than the other
direct variations we’ve studied?
10. Graph the inverse variation y = -6/x.
How is it different from the other inverse
variations we’ve studied?
11. Why is this graph not a direct variation?
12. For each situation: make a table of values, a graph and write an equation. Direct or inverse?
Situation #1: Michael is driving at 25 miles per hour. (input hours, output distance)
Situation #2: A group yoga class costs $120. (Input number of students, output ost per student)