(r+6)(r-6)=0

Solution for (r+6)(r-6)=0 equation:

Simplifying
(r + 6)(r + -6) = 0

Reorder the terms:
(6 + r)(r + -6) = 0

Reorder the terms:
(6 + r)(-6 + r) = 0

Multiply (6 + r) * (-6 + r)
(6(-6 + r) + r(-6 + r)) = 0
((-6 * 6 + r * 6) + r(-6 + r)) = 0
((-36 + 6r) + r(-6 + r)) = 0
(-36 + 6r + (-6 * r + r * r)) = 0
(-36 + 6r + (-6r + r2)) = 0

Combine like terms: 6r + -6r = 0
(-36 + 0 + r2) = 0
(-36 + r2) = 0

Solving
-36 + r2 = 0

Solving for variable 'r'.

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

Add '36' to each side of the equation.
-36 + 36 + r2 = 0 + 36

Combine like terms: -36 + 36 = 0
0 + r2 = 0 + 36
r2 = 0 + 36

Combine like terms: 0 + 36 = 36
r2 = 36

Simplifying
r2 = 36

Take the square root of each side:
r = {-6, 6}