Question

i dont know how to set it up???!!!
y varies directly as the square of x. When x = 2, y = 40. Find x when y = 640.

Answer 1

@Lizzyeb631
it is given
y is proportional to sqr(x)
Note :- we always replace proportional sign with some constant
let us say this constant is K
therefore
y = K* sqr(x)
from the given value of x and y . find the value of constant ( K ) first