(X-20)(X+20)=

Solution for (X-20)(X+20)= equation:

Simplifying
(X + -20)(X + 20) = 0

Reorder the terms:
(-20 + X)(X + 20) = 0

Reorder the terms:
(-20 + X)(20 + X) = 0

Multiply (-20 + X) * (20 + X)
(-20(20 + X) + X(20 + X)) = 0
((20 * -20 + X * -20) + X(20 + X)) = 0
((-400 + -20X) + X(20 + X)) = 0
(-400 + -20X + (20 * X + X * X)) = 0
(-400 + -20X + (20X + X2)) = 0

Combine like terms: -20X + 20X = 0
(-400 + 0 + X2) = 0
(-400 + X2) = 0

Solving
-400 + X2 = 0

Solving for variable 'X'.

Move all terms containing X to the left, all other terms to the right.

Add '400' to each side of the equation.
-400 + 400 + X2 = 0 + 400

Combine like terms: -400 + 400 = 0
0 + X2 = 0 + 400
X2 = 0 + 400

Combine like terms: 0 + 400 = 400
X2 = 400

Simplifying
X2 = 400

Take the square root of each side:
X = {-20, 20}