The equation is .

The perfect square of the given trinomial .

                         (Take the square root of each side)

Apply square roots property: If then .

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

                   (Subtract 7 from each side)

                               (Apply additive inverse property: )

Using the calculator to evaluate each value of x.

And using the calculator to evaluate square roots: . 

                      (Simplify)

The solution set is .