suppose x varies jointly as y and z^2. Furthermore, x is 252 when y is 7 and z is 3. Find x when y is 3 and z is 5.

Answer 1

x varies jointly as y and z^2

x=k*y*z^2

Need to determine constant k.

Give x = 252 when y is 7 and z is 3, so can substitute for those i the above equation to find k.

252= k*7*3^2

6 = k

So final equation of variation is below:

x = 6*y*z^2

We can use that equation to find x, when y is 3 and z is 5.

x = 6*3*5^2

x = 450

Answer 2

Joint Variation: x(y,z²)

Therefore, x=kyz²

Substitute: 252=k(7)(3²) —> k=4

Now, find new X value: x=(4)(3)(5²)=300