Question

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

Answer 1

See the entire solution process below:

Explanation:

Because the is no `x` term we can solve directly for `x^2`.

First, add `color(red)(8)` to each side of the equation to isolate the `x^2` term while keeping the equation balanced:

`x^2 - 8 + color(red)(8) = 13 + color(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) = +-sqrt(21)`

`x = +-sqrt(21) = +-4.583` rounded to the nearest thousandth.