Question

Solve the system by substitution. X = 9y 2x - 2y = -16

Answer 1

`\begin{gathered} \begin{bmatrix}x=9y \\ 2x-2y=-16\end{bmatrix} \\ 2\cdot\: 9y-2y=-16 \\ 18y-2y=-16 \\ 16y=-16 \\ (16y)/(16)=-(16)/(16) \\ y=-1 \end{gathered}`

then solve for x

`\begin{gathered} x=9\mleft(-1\mright) \\ x=-9 \end{gathered}`

answer:

x = -9

y = -1