for the one on the left:
distribute: -18x + 27 - 10x = -1
combine like terms: -28x + 27 = -1
subtract 27 from both sides: -28x = -28
divide -28: x = 1
on the right:
distribute: 10x - 15 + 8 = 9
combine like terms: 10x - 7 = 9
add 7 to both sides: 10x = 16
divide: x = 1.6
