\(2m=-4n-4 \ \ \ |\times (-3) \\
3m+5n=-3 \ \ \ |\times 2 \\ \\
-6m=12n+12 \\
\underline{6m+10n=-6} \ \ \ |\hbox{add the sides of the equations} \\
10n=12n+12-6 \\
10n=12n+6 \ \ \ |-12n \\
-2n=6 \ \ \ |\div (-2) \\
n=-3 \\ \\
2m=-4n-4 \\
2m=-4 \times (-3)-4 \\
2m=12-4 \\
2m=8 \ \ \ |\div 2 \\
m=4 \\ \\
(m,n)=(4,-3)\)
