Question 773363
{{{system(2x+y=-1, y=x+8)}}}
Substitute {{{y=x+8}}} into the first equation of the system
{{{2x+(x+8)=-1}}}
{{{2x+x+8=-1}}}
{{{3x=-9}}}
{{{x=-3}}}
Substitute {{{x=-3}}} into {{{ y=x+8}}}
{{{y=-3+8}}}
{{{y=5}}}
{{{system(x=-3, y=5)}}} - the solution of the system
Check the answer
{{{system(2*(-3)+5=-1, 5=-3+8)}}}
{{{system(-1=-1, 5=5)}}} - correct
Answer: (-3, 5)