Substitute -6x-7 for y in the equation 7x+y=-3 to obtain the value of the of x.
[tex]\begin{gathered} 7x-6x-7=-3 \\ x=-3+7 \\ =4 \end{gathered}[/tex]Substitute 4 for x in the equation y=-6x-7 to obtain the value of the y.
[tex]\begin{gathered} y=-6\cdot4-7 \\ =-24-7 \\ =-31 \end{gathered}[/tex]So solution of the equation is (4,-31).