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

1 Answer
smendyka
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 #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.

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