We have
[tex]\begin{gathered} y=7x+10 \\ y=-4x-23 \end{gathered}[/tex]
we make the next equality
[tex]7x+10=-4x-23[/tex]
then we sum like terms
[tex]7x+4x=-23-10[/tex][tex]\begin{gathered} 11x=-33 \\ x=\frac{-33}{11}=-3 \end{gathered}[/tex]
Then we substitute the value of x in the first equation
[tex]\begin{gathered} y=7(-3)+10 \\ y=-21+10 \\ y=-11 \end{gathered}[/tex]
ANSWER
x=-3
y=-11
