To solve the problem, we notice that both of the equations are written with the y solved then we can equate the expressions of x and solve the resulting equation of x:
[tex]\begin{gathered} x-12=-3x+12 \\ x+3x=12+12 \\ 4x=24 \\ x=\frac{24}{4} \\ x=6 \end{gathered}[/tex]
Once we have the value of x we plug it on the first equation to find y:
[tex]\begin{gathered} y=6-12 \\ y=-6 \end{gathered}[/tex]
Therefore, the solution of the system of equations is (6,-6)
