## Intermediate Algebra (6th Edition)

Reorder $n^{2}$ + n = 72 to $n^{2}$ + n - 72 1. Factor: $n^{2}$ + n - 72 = (n + 9)(n - 8) 2. Apply the zero factor property to the factored expression: a) n + 9 = 0 b) n - 8 = 0 3. Solve each linear equation: a) n = -9 b) n = 8 The solutions are {-9, 8}.