You can put this solution on YOUR website! x+y=-8
y=2x+7
.
rewrite second equation:
x+y=-8
-2x+y= 7
.
multiply bottome equation by -1 and add both equations together:
x+y=-8
2x-y=-7
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3x = -15
x = -5
.
substitute above into:
x+y=-8
-5+y=-8
y = -3
.
answer:(x,y) = (-5, -3)
