(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}