Question

The value of y varies directly with x. Which function represents the relationship between x and y if y=20/3 when x=30?

Answer 1

`y=2/9x`

Explanation:

If `y` varies directly with `x`
then
`color(white)("XXX")y=k * x` for some constant `k`

Given `x=30rarr y=20/3`
implies
`color(white)("XXX")20/3 = k * 30`

`color(white)("XXX")rarr k=(20/3)/30=20/90=2/9`