Background To solve an equation, use inverse operations.
Whatever operation is done to one side of the
equation must be done to the other side to make
an equivalent equation.
If a = b, then a + c = b + c.
If a = b, then a  c = b  c.
If a = b, then ac = bc.
If a = b, and c ≠ 0, then a / c = b / c. 
WarmUp n  8 = 12 matches n =
20.
â€œIf you add 8 to both sides, then n = 20.â€
WarmUp
2n + 3 = 15 matches n = 6.
â€œFirst subtract 3 from each side to get 2n = 12.
Then divide both sides by 2 to get n = 6.â€
