Determine the equation of combined variation. Then solve for the missing value.

x varies directly with y and inversely with z.
x = 5 when y = 10 and z = 5.
Find x when y = 20 and z = 10.

1 answer

x = ky/z

5 = k(10)/(5) ==> k = 5/2

x(20,10) = (5/2)(20)/(10) = 5