Question

If y varies directly with x, and y = 0.7 when x = 0.4, how do you write the direct linear variation equation?

Answer 1

`y=7/4 x`

Explanation:

Using ratio:

`y/x ->(0.7)/ (0.4)`

So`" "y/x-> (0.7xx10)/(0.4xx10)=7/4`

Multiply both sides by `x` giving

`yxxx/x=7/4 x`

But `x/x = 1` giving:

`y=7/4 x`