9x - 4x + 16 - 4 = 53
Combine the 9x - 4x as 5x and put 5x in place of 9x - 4x
5x + 16 - 4 = 53
Combine the + 16 - 4 as + 12 and put + 12 in place of + 16 - 4
5x + 12 = 53
Add - 12 to both side to cancel away the + 12 on the left
5x + 12 = 53
- 12 -12
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5x = 41
Divide both sides by 5
Cancel the 5's:
Edwin
