Question

Substitutionx+y=-2-2x-y=8

Answer 1

Solve the system

`\begin{gathered} x+y=-2 \\ -2x-y=8 \\ \end{gathered}`

We clear x from x + y = -2:

`\begin{gathered} x+y-y=-2-y \\ x=-2-y \end{gathered}`

We substitute x in the second equation and simplify:

`\begin{gathered} -2(-2-y)-y=8 \\ 4+2y-y=8 \\ 4+y=8 \end{gathered}`

We clear y:

`\begin{gathered} 4+y-4=8-4 \\ y=4 \end{gathered}`

We substitute y in x = -2 - y:

`x=-2-4=-6`

Answer:

x = - 6

y = 4