Question 832634
1.{{{7A+3B=-1}}}
2.{{{A+B=-3}}}
Multiplying eq. 2 by 3 and subtract from eq. 1,
{{{7A+3B-3A-3B=-1+9}}}
{{{4A=8}}}
{{{A=2}}}
Then use either equation to solve for {{{B}}}.
{{{2+B=-3}}}
{{{B=-5}}}