y=2x+1
3x + y=-9
3x + y=-9 is the same as y=-3x-9
y=2x+1
y=-3x-9
2x+1 = -3x-9
—-add 3x on both sides
5x+1=-9
—-subtract 1 from both sides
5x=-10
—-divide 5 on both sides
5x/5 = -10/5
x = -2
——now plug in x in one of the equations to find y
y=2x+1
y=2(-2)+1
y=-4+1
y=-3
The solution is (-2,-3).
