Practicing Direct Variation

The first of each section is done for you as an example.

Determine whether the values in the table represent direct variation. If so, write the
equation for variation.
1.
x  2 3 4 5 6
y 4 9 16 25 36

Yes, x2 = y

2.
x  0 1 2 3 4
y 10 12 14 16 18

3.
x  5 10 15 20 25
y 10 20 30 40 50

For 4-10, y varies directly as x (y = kx). Find the constant of proportionality and
write the equation that relates x and y.

4. y = 21 when x = 7  3x = y

5. y = 2 when x = 1

6. y = 1 when x = 1/3

7. y = 24 when x = 8

8. y = 12 when x = ¼

9. y = 4 when x = 20

 

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