Question

The value of y varies directly with x, and y= -8 when x=2. How do you find y when x=3?

Answer 1

When `x=3`, we have `y=-12`

Explanation:

As value of `y` varies directly with `x`, we have `ypropx`

i.e. `y=kxx x`, where `k` is a constant.

AS `y` takes a value `y=-8`, when `x=2`

we have `-8=kxx2` or `k=-8/2=-4`

Hence, relation is `y=-4x`

and when `x=3`, we have `y=-4xx3=-12`