Answer :
[tex]2x+y=20 \\
6x-5y=12 \\ \\
\hbox{solve the first equation for y:} \\
2x+y=20 \ \ \ |-2x \\
y=20-2x \\ \\
\hbox{substitute 20-2x for y in the second equation:} \\
6x-5(20-2x)=12 \\
6x-100+10x=12 \\
16x-100=12 \ \ \ |+100 \\
16x=112 \ \ \ |\div 16 \\
x=7 \\ \\
y=20-2x=20-2 \times 7=20-14=6 \\ \\
\boxed{(x,y)=(7,6)}[/tex]
