Question

1 If y = 7 when x= 3, find y when x=5, given that y varies directly with x.

Answer 1

Answer:

y1/x1 = y2/x2 ⇒

y2 = (x2/x1) y1

Plug in

x1 = 3

y1 = 7

x2 = 7

and get y2.