The qudractic expression is .

               (Add 9 to each side)

                   (Add: )

The perfect square of the given trinomial .

Apply square roots property: If , then .

              (Take square root each side) \ \

Apply addition property of equality: If a = b then a c = b c.

                (Add 3 to each side)

                            (Apply additive inverse property: )

Separate the solutions .

The solution set is .