How do you solve 11^ { 2} + x ^ { 2} = 23^ { 2}?

1 Answer
Dec 11, 2017

x=+-2sqrt102

Explanation:

First, let's subtract 11^2 from both sides.

x^2=23^2-11^2
x^2=529-121
x^2=408

Take the square root of both sides

x=+-sqrt408

x=+-2sqrt102

Why do we have plus or minus? Well, what is (sqrt408)^2? 408.
How about (-sqrt408)^2. This is 408 as well. So x can take both the positive and negative values.