Direct and Inverse Variation

Direct or Inverse

100

y=7/x

Inverse

200

y=4x

Direct

300

r=9/d

Inverse

400

y=-14x

Direct

Constant of Variation

100

Given y=-5x, what is the constant of variation

-5

200

If y varies inversely with x and y=40 when x=16. What is the constant of variation?

k=640

300

If y varies directly with x and y=28 when x=7.

k=4

400

If y varies directly with x and y=-4 when x=2. What is the constant of variation?

k=-2

Direct Variation

100

If y varies directly and y=2 when x=6. find y when x=9

y=3

200

If y varies directly with x and y=80 when x=16. Find y when x=3.

y=15

300

Given y varies directly with x and y=7 when x=14. Find x when y=9.

x=18

400

Y varies directly with x, use the specified values to write a direct variation equation that relates x and y. x=9 y=27

y=3x

Inverse Variation

100

Given that y varies inversely with x and y=3 when x=2. Find y when x=3

y=2

200

Given that y varies inversely with x and y=.5 when x=10. Find y when x=2

y=2.5

300

If y varies inversely with x and y=9 when x=1. What is x when y=3.

x=3

400

If y varies inversely with x and y=1/3 when x=9. Find x when y=9

x = 1/3