[tex]x+5y=7 \\
x+3y=1 \ \ \ \ \ \ \ \ \ \ \ |\times (-1) \\ \\
x+5y=7 \\
\underline{-x-3y=-1} \\
5y-3y=7-1 \\
2y=6 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ |\div 2 \\
y=3 \\ \\
x+3y=1 \\
x+3 \times 3=1 \\
x+9=1 \ \ \ \ \ \ \ \ \ \ \ \ \ |-9 \\
x=-8 \\ \\ \boxed{(x,y)=(-8,3)}[/tex]
