Solve Using the Square Root Property x^2-8=10

$x^{2} - 8 = 10$

Step 1

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

Add $8$ to both sides of the equation.

$x^{2} = 10 + 8$

Add $10$ and $8$ .

$x^{2} = 18$

Step 2

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

$x = \pm \sqrt{18}$

Step 3

Simplify $\pm \sqrt{18}$ .

Rewrite $18$ as $3^{2} \cdot 2$ .

Factor $9$ out of $18$ .

$x = \pm \sqrt{9 (2)}$

Rewrite $9$ as $3^{2}$ .

$x = \pm \sqrt{3^{2} \cdot 2}$

Pull terms out from under the radical.

$x = \pm 3 \sqrt{2}$

Step 4

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.

$x = 3 \sqrt{2}$

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

$x = - 3 \sqrt{2}$

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

$x = 3 \sqrt{2}, - 3 \sqrt{2}$

Step 5

The result can be shown in multiple forms.

Exact Form:

$x = 3 \sqrt{2}, - 3 \sqrt{2}$

Decimal Form:

$x = 4.24264068 \dots, - 4.24264068 \dots$