The variable x varies directly as the square of y, and y varies directly as the cube of z. If x equals −16 when z equals 2, what is the value of x when z equals 12?
+37165 x = ky^2 y = k/z^3 combined x = k /z^6
-16 = k/ 2^3
k = -128
x = -128 / z^6
x = -128 / (1/2)^3 = -1024
