Y Varies directly with w and the square of x and inversely with z

Question

Suppose that y varies directly with w and the square of x and inversely with z, and y=9 when w=2, x=3, and z=10. Find y when w=4, x=5, and z=25.

Answer 1

y = kwx²/z  where k is a constant

 

to calculate the value of k, plug in the values in the example you have been given.

 

(9) = k(2)(3)²/10 = k 18/10

10(9)/18 = k

k = 5

 

now, take the data for the second example, but this time you have k and must solve for y.

 

y = 5 wx²/z

 

y = 5(4)(5)²/25 = 20