Question

Suppose z varies directly with x and inversely with the square of y. If z = 16 when x = 4 and y = 1 , what is z when x = 8 and y = 9 ?

Answer 1

Answer:

z = 3.6

Step-by-step explanation:

Given that,

z varies directly with x and inversely with the square of y. We can write it as :

$z\propto \dfrac{x}{y}\\\\z=\dfrac{kx}{y}$

Where

k is constant

Put z = 16 when x = 4 and y = 1

$16=\dfrac{k\times 4}{1}\\\\k=4$

Now put k = 4, x = 8 and y = 9

$z=\dfrac{4\times 8}{9}\\\\z=3.6$

So, the value of z is equal to 3.6.