addition method is the best because we have a variable with its opposite numbers, so adding them will eliminate
so we will get Y in an instant
[tex]\begin{gathered} 5x+4y=-7 \\ -5x-2y=1 \\ ------------ \\ 0x+2y=-6 \end{gathered}[/tex][tex]\begin{gathered} 2y=-6 \\ y=-3 \end{gathered}[/tex]now, we can replace on any equation to solve x
[tex]\begin{gathered} 5x+4(-3)=-7 \\ 5x-12=-7 \\ 5x=-7+12 \\ x=\frac{5}{5} \\ x=1 \end{gathered}[/tex]