The value of y varies jointly with the values of x and z. When x=4x=4 and z=9z=9, the value of y is 360. What is the value of y when x=5x=5 and z=12z=12?

Question

 please help this is timed and i need an answer quick 

Answer 1

This joint variation can be represented by the following equation:

 

y = kxz

 

where k = constant of proportion or proportionality constant

 

First, calculate the value of k

 

When x = 4, z = 9, y = 360, then

 

360 = k(4)(9)

 

360 = 36k

 

k = 360 / 36

 

k = 10

 

Substitute this value of k in the equation.

 

Thus, y = 10xz

 

When x = 5, z = 12, then

 

y = 10(5)(12)

 

y = 600