Question

if y varies jointly with the square of x and inversely as z, what is the change in y when both x and z are tripled

Answer 1

Explanation:

y = x^2 / z now triple x and z

y = (3x)^2 / 3z = 9x^2 / 3z = 3 * x^2 / z <==== this is 3 times the original

y is tripled