Respuesta :

Answer:

The value of y=6

Step-by-step explanation:

Given that y varies directly with x

Using the formula

y ∝ x

y=kx

Where k is the constant of proportionality

In order to find 'k' use the given condition

y=8  when  x=20

y=kx

k=y/x  

 = 8/20

 = 2/5

Thus, the equation to find 'y' is

y=2/5x

when x=15 then

y=2/5(15)

 = 6

Thus, the value of y=6