The equation is .

Add to each side. \ \

Rewrite the equation .

Group terms with common factors.

Factor the G.C.F from each grouping.

Combine like terms using distributive property: .

Apply zero product property: If ab = 0 then a = 0, b = 0.

First .

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

Subtract 15 from each side.

Apply additive inverse property: .

Second .

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

Subtract 1 from each side.

Apply additive inverse property: .

Check:

To check the solution substitute  in .

           (Product of two same sings is positive)

The first solution is true.

To check the solution substitute  in .

               (Product of two same sings is positive) \ \

The second solution is true.

The values of .