Name:___________________________
IP#5-3 Direct Variation
Recognizing a Direct Variation
From an Equation
From a Table (Ordered Pairs)
From a graph
From an equation: Tell whether each equation represents a direct variation. If so, identify the constant of variation, k.
1.
2.
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5.
6.
7.
4.
=0
8.
From a table or ordered pairs. Tell whether each relationship is a direct variation. If yes, give the ratio.
9.
X
1
2
3
4
Y
-5
-4
-3
-2
10.
X
1
2
3
4
Y
-2
-4
-6
-8
11.
12.
x 10 5 2
y 12 7 4
From a graph: State if the graph indicates that x and y vary directly, and why or why not.
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x 1 2 3
y 1 2 3
21. The migration of snow geese varies directly as the number of hours. A flock of snow geese migrated 375 miles in 7.5
hours. Write a direct variation equation for the distance d flown in time t. At this rate, how long would it take the
snow geese to travel 3000 miles?
22. A hot air balloon’s ascent varies directly as the number of minutes. A hot air balloon ascended 350 feet in 5 minutes.
Write a direct variation equation for the distance d ascended in time t. How many minutes will it take the hot air
balloon to ascend 2100 feet.
23. Your pay varies directly as the number of hours you work. Your pay for 7.5 hours is $45. Write a direct variation
equation for your pay p to the hours worked t. Find your pay if you work 30 hours.
24. A school purchased five new basketballs for #$149.95. Write a direct variation equation for the number of
basketballs b to the amount spent m. At that rate, how much more money will it cost the school to have 12 new
basketballs in all?
25. Most animals age more rapidly than humans do. The chart shows equivalent ages for horses and humans.
Horse age (x)
0 1 2 3 4 5
Human age (y) 0 3 6 9 12 15
Write an equation that relates human age to horse age. Find the equivalent horse age for a human who is 16 years old.
26. The Ramirez family is driving cross country on vacation. They drive 330 miles in 5.5 hours. Write a direct variation
equation to find the distance driven for any number of hours. Estimate how long it would take them to drive 600 miles.