44.4k views
13 votes
Solve by using Substitution: 3x-y=13 2x +2y = -10​

1 Answer

3 votes
3x-y=13
2x + 2y = -10

change 2x + 2y = -10 into slope intercept form, making the equation y = -x -5. insert y = -x - 5 into 3x - y = 13, making the new equation 3x + x - 5 = 13. Add alike terms together (3x + x = 4x) then add 5 to both sides, making the new equation 4x = 18. divide both sides by 4, making x = 6. Insert 6 back into the old equation of y = - x - 5, making the old equation y = - 6 - 5. Add alike terms (- 6 - 5 = - 11) making y = -11 and x = 6. (6, -11) would be the ordered pair.