Question

If the vault of y varies directly with x and y =-8 when x=4 find y when x =-4

Answer 1

Solution;

$\begin{gathered} y\propto x \\ y=kx \end{gathered}$$\begin{gathered} When\text{ y=-8 and x=4;} \\ -8=4k \\ k=-\frac{8}{4}=-2 \end{gathered}$$\begin{gathered} When\text{ x=-4, y=?} \\ y=-2(-4) \\ y=8 \end{gathered}$

Answer;

y=8