**Completing the Square**

We can solve quadratic equations like 3x^{2} = 6 and (x – 2)^{2} = 7 by using

the principle of square roots. We can also solve an equation such as x^{2} + 6x + 9 = 2

in like manner because the expression on the left side

is the square of a binomial,(x + 3)^{2} . This second procedure is the basis for

a method called **completing the square. ***It can be used to solve any quadratic*

*equation*.

**Important Notes**

When solving an equation, to complete the square of an expression like x^{2} + bx, we take half the x-coefficient, which is b/2, and square it. Then we add the number, (b/2)^{2}, on both sides of the equation.