How do you solve x^2 = 121?

I'm confused on how to get this.
Can someone help me solve x^2 = 121?

1 Answer
Jun 5, 2018

You take the square root of both sides and make the right side have +- signs. Or you can write in standard form and factor.

Explanation:

Given x^2 = 121

Take the square root of both sides (don't forget the +- on the right):

x = +-11

This separates into:

x = 11 and x = -11

Another way to do it is:

Given x^2 = 121

Write in standard form by subtracting 121 from both sides:

x^2-121=0

The form x^2-c always factors into (x+sqrtc)(x-sqrtc):

(x+11)(x-11) = 0

Set both factors equal to 0:

x +11=0 and x-11=0

x = -11 and x = 11 larr same answer