(p-9)(p+9)=0

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

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

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

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

Multiply (-9 + p) * (9 + p)
(-9(9 + p) + p(9 + p)) = 0
((9 * -9 + p * -9) + p(9 + p)) = 0
((-81 + -9p) + p(9 + p)) = 0
(-81 + -9p + (9 * p + p * p)) = 0
(-81 + -9p + (9p + p2)) = 0

Combine like terms: -9p + 9p = 0
(-81 + 0 + p2) = 0
(-81 + p2) = 0

Solving
-81 + p2 = 0

Solving for variable 'p'.

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

Add '81' to each side of the equation.
-81 + 81 + p2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + p2 = 0 + 81
p2 = 0 + 81

Combine like terms: 0 + 81 = 81
p2 = 81

Simplifying
p2 = 81

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