Question 1066712
Multiply eq. 2 by 4 and subtract from eq. 1 multiplied by 3,
{{{3(4x-3y)-4(3x+7y)=3(11)-4(-1)}}}
{{{12x-9y-12x-28y=33+4}}}
{{{-37y=37}}}
{{{y=-1}}}
Now use either equation to solve for {{{x}}}.