Question

How do you determine the constant of variation for the direct variation given `-5y=2x`?

Answer 1

`k=-2/5`

Explanation:

In a direct variation, the constant variation `k` is equal to `y/x`.

`k=y/x`

We just need to isolate `y/x` in one side.

Solution
`−5y=2x`
`(1/(2x))(−5y)=(1/(cancel(2x)))(cancel(2x))`
`(-5y)/(2x)=1`
`(cancel2/cancel(-5))((cancel(-5)y)/(cancel2x))=(2/-5)1`
`color(red)(y/x=-2/5=k)`