Question

8) -7x-2y=-13 x-2x= 11 1

Answer 1

`\begin{cases}-7x-2y=-13 \\ x-2y=11\end{cases}\rightarrow\begin{cases}7x+2y=13 \\ x-2y=11\end{cases}\rightarrow8x=24\rightarrow x=(24)/(8)=3`

having that x=3 we get

`3-2y=11\rightarrow-2y=11-3=8\rightarrow y=-(8)/(2)=-4`

so the answer is x=3 and y=-4

`x-2y=11\rightarrow x=11+2y`

having that we can replace in the first equation

`\begin{gathered} -7\cdot(11+2y)-2y=-13\rightarrow-77-14y-2y=-13\rightarrow-16y=64 \\ y=-(64)/(16)=-4 \end{gathered}`

having that y=-4 we get

`x=11+2\cdot-4=11-8=3`