Question 858151
 
 
multiply both sides of x+y=5 by four to get:
{{{4x+4y=20}}}
Subtract that from the first like so:
 {{{4x+7y=-1}}}
-{{{4x+4y=20}}}
_______________
 {{{3y=-21}}}
Divide both sides by 3:
{{{y=-7}}}
Plug that in to the second equation:
{{{x-7=5}}}
Add 7 to both sides:
{{{x=12}}}
Your answers are <b>X=12 </b>and<b> Y=-7</b>
To check, plug both into the first equation:
{{{4*12+7*-7=-1}}}
{{{48-49=-1}}}
{{{-1=-1}}}
Success!