Answer:
D. -10, 10
Explanation:
Instead of inserting values into x to solve, let's isolate x.
In order to do this, we must take the square root of both sides.


To find the square root of 100, we must figure out what = 100 when multiplied by itself. Reminder, it can be both a positive or a negative square root, as positive times positive is a positive, and negative times negative is a positive.
The square root of 100 is -10 or 10, as 10 x 10 or -10 x -10 = 100.
Hope this helps! :)