Solve each system of equations using substitution. Show all work.
1) x - y = 2
4x - 3y = 11
2) -2x + 3y = 14
x + 2y = 7
3) 6x - y = -4
2x + 2y = 15
1) x - y = 2
4x - 3y = 11
2) -2x + 3y = 14
x + 2y = 7
3) 6x - y = -4
2x + 2y = 15