Question

The variables x and y vary directly. Write an equation that relates x and y, when x = 4 and y = 2

Answer 1

Since x & y vary directly  (it means when x increases, y increases & vice versa)
Then the equation==> y = k.x (k is a constant to be calculated)

But x=4 and y= (given) ==> 2=4k or k= 1/2 & the equation becomes y=1/2 (x)