# How do you solve x^2 - 8 = 13?

Feb 8, 2017

See the entire solution process below:

#### Explanation:

Because the is no $x$ term we can solve directly for ${x}^{2}$.

First, add $\textcolor{red}{8}$ to each side of the equation to isolate the ${x}^{2}$ term while keeping the equation balanced:

${x}^{2} - 8 + \textcolor{red}{8} = 13 + \textcolor{red}{8}$

${x}^{2} - 0 = 21$

${x}^{2} = 21$

Now, take the square root of each side of the equation to solve for $x$ while keeping the equation balanced. The square root of number will return both a negative and positive result:

$\sqrt{{x}^{2}} = \pm \sqrt{21}$

$x = \pm \sqrt{21} = \pm 4.583$ rounded to the nearest thousandth.