(w+9)(w-9)=

Solution for (w+9)(w-9)= equation:

Simplifying
(w + 9)(w + -9) = 0

Reorder the terms:
(9 + w)(w + -9) = 0

Reorder the terms:
(9 + w)(-9 + w) = 0

Multiply (9 + w) * (-9 + w)
(9(-9 + w) + w(-9 + w)) = 0
((-9 * 9 + w * 9) + w(-9 + w)) = 0
((-81 + 9w) + w(-9 + w)) = 0
(-81 + 9w + (-9 * w + w * w)) = 0
(-81 + 9w + (-9w + w2)) = 0

Combine like terms: 9w + -9w = 0
(-81 + 0 + w2) = 0
(-81 + w2) = 0

Solving
-81 + w2 = 0

Solving for variable 'w'.

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

Add '81' to each side of the equation.
-81 + 81 + w2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + w2 = 0 + 81
w2 = 0 + 81

Combine like terms: 0 + 81 = 81
w2 = 81

Simplifying
w2 = 81

Take the square root of each side:
w = {-9, 9}