Solve Using the Square Root Property (x+9)^2=64

${(x + 9)}^{2} = 64$

Step 1

Take the specified root of both sides of the equation to eliminate the exponent on the left side.

$x + 9 = \pm \sqrt{64}$

Step 2

Simplify $\pm \sqrt{64}$ .

Rewrite $64$ as $8^{2}$ .

$x + 9 = \pm \sqrt{8^{2}}$

Pull terms out from under the radical, assuming positive real numbers.

$x + 9 = \pm 8$

Step 3

The complete solution is the result of both the positive and negative portions of the solution.

First, use the positive value of the $\pm$ to find the first solution.

$x + 9 = 8$

Move all terms not containing $x$ to the right side of the equation.

Subtract $9$ from both sides of the equation.

$x = 8 - 9$

Subtract $9$ from $8$ .

$x = - 1$

Next, use the negative value of the $\pm$ to find the second solution.

$x + 9 = - 8$

Move all terms not containing $x$ to the right side of the equation.

Subtract $9$ from both sides of the equation.

$x = - 8 - 9$

Subtract $9$ from $- 8$ .

$x = - 17$

The complete solution is the result of both the positive and negative portions of the solution.

$x = - 1, - 17$