Respuesta :

Answer:

i)  y∝x  => y = kx and k = 2.5

ii) When x = 7, y is 17.5

Step-by-step explanation:

If y is directly proportional to x then according to the question

y∝x  which means y =kx where k is any constant

From the above example

8y=20x comparing it with y = kx

y =  (20/8)x

y = 2.5x

Here k = 2.5

i) y∝x  =>  y =2.5x

ii) if x=7 then y = ?

From above

y=2.5x

Put x = 7

y = 2.5 x 7

y = 17.5