Question

How do you find the equation given that y varies directly with x, write the linear function relating the two variables and when x=3 y=6?

Answer 1

`y = 2 x`

Explanation:

`y` varies directly with `x` means
`y = k x`, where `k` is a constant.

plug `y =6` and `x = 3` into the above equation,

`6 = k (3)`
divided by `3`,
`2 = k`.

therefore the answer is
`y = 2 x`