Question

2. The value of y varies directly with x. When y = 45, x = 4. What is the

value of y when x is 7?

Answer 1

direct variation means y=kx (inverse variation is yx=k or y=k/x)

so we are given that:

75=k/2, so k=150 which means:

y=150x now

y(2.25)=150(2.25)=337.5