x² - 36 = 0
Add 36 to both sides.
x² = 36
So, basically what you're doing is finding the square root of 36.
The square root of 36 is 6 AND -6
So, x = 6 AND x = -6
x can equal both because if you multiply 6 with 6, you'll get 36, and if you multiply -6 with -6, you'd still get 36.
~Hope I helped!~
