The value of y varies jointly with the values of x and z. When x=4 and z=9, the value of y is 360.

What is the value of y when x=5 and z=12?

2 answers

y = k (xz)
when x=4, z = 9, y = 360
360 = k(36)
k = 10
so y = 10xz

sub in your given values to find y
its 600 there you go.