Answer:
Substitution is when you isolate a variable-
3) We can divide the first equation by 6 to get x+y=-1, then isolate to get y=-1-x. We plug this into the second equation to have 3x+(-1-x)=-13. We simplify and get 2x=-12 so x=-6. We plug this back into the first equation and get -6+y=-1 so y=5. So the answer as an ordered pair is (-6,5).
4) We can isolate the second equation to get x=2y+11. We substitute this into the first equation to have -7(2y+11)-2y=-13. We simplify and get -16y=64 so y=-4. We plug this back into the second equation and get x+8=11 so x=3. So the answer as an ordered pair is (3,-4).
