### Home > A2C > Chapter 3 > Lesson 3.2.3 > Problem 3-129

3-129.

Solve

Square both sides of the equation.

4*x*^{2} = 8*x* + 12

Simplify and solve the resulting equation.

*x*^{2} − 2*x* − 3 = 0

*x* = 3. But, −1 does not work in the original equation.

Substitute each answer in the original equation. Only one of them will satisfy the equation.

6 = 6

−2 = 2