Direct Variation
Example 1: Write a direct variation equation that has (3,-9) as a solution.
k=
equation:_________
Example 2: p varies directly as z. If p = 210 when z =
200, write the formula for the relation between p and z.
Inverse Variation
Example 1: Suppose that y varies inversely as x and that y = 8 when x = 3. Form an
equation relating x and y. Calculate the value of y when x = 10.
Example 2: Variables x and y vary inversely; y=7 when x=4. Write an
equation that relates x and y then find y when x=-2.
Joint Variation
Example 1: x varies inversely with y and directly with w.
Write an equation for the given relationship.
Example 2: The variable z varies jointly with x and y. Use the
given values to write an equation relating x, y, and z. x=1, y=2, z=7.
k=_____
equation:___________
Combined Variation
Example 1: Write an equation for the given relationship.
a varies directly with b and inversely with the cube of c.
Example 2: m varies directly as n and inversely as p. Given two sets
of values below, find the missing value.
First set: m = 10, n = 4, p = 8
Second set: m = ?, n = 20, p = 40