Question

“y varies jointly as x and z”. Write the appropriate joint-variation equation, and then find “y” for the given value of “x” and “z”.

y = 12 when x = 4 and z = 5, find “y” when x = 6 and z = 3.

Answer 1

y = kxz. y = 10.8

Explanation:

y = kxz, where k is a constant.

12 = k(4)(5) = 20k

k = 12/20 = 0.6.

y = kxz

= (0.6) (6) (3)

= 10.8