(v+9)(v-9)=0

Solution for (v+9)(v-9)=0 equation:

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

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

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

Multiply (9 + v) * (-9 + v)
(9(-9 + v) + v(-9 + v)) = 0
((-9 * 9 + v * 9) + v(-9 + v)) = 0
((-81 + 9v) + v(-9 + v)) = 0
(-81 + 9v + (-9 * v + v * v)) = 0
(-81 + 9v + (-9v + v2)) = 0

Combine like terms: 9v + -9v = 0
(-81 + 0 + v2) = 0
(-81 + v2) = 0

Solving
-81 + v2 = 0

Solving for variable 'v'.

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

Add '81' to each side of the equation.
-81 + 81 + v2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + v2 = 0 + 81
v2 = 0 + 81

Combine like terms: 0 + 81 = 81
v2 = 81

Simplifying
v2 = 81

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