Question 951115
Since opposite sides are congruent.
{{{6y-6=2x+20}}}
{{{-2x+6y=26}}}
1.{{{x-3y=-13}}}
and
{{{3x+21=6y}}}
{{{x+7=2y}}}
2.{{{x-2y=-7}}}
Subtract eq. 1 from eq. 2,
{{{x-2y-x+3y=-7+13}}}
{{{y=6}}}
So then,
{{{x-3(6)=-13}}}
{{{x-18=-13}}}
{{{x=5}}}