(t+9)(t-9)=0

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

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

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

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

Multiply (9 + t) * (-9 + t)
(9(-9 + t) + t(-9 + t)) = 0
((-9 * 9 + t * 9) + t(-9 + t)) = 0
((-81 + 9t) + t(-9 + t)) = 0
(-81 + 9t + (-9 * t + t * t)) = 0
(-81 + 9t + (-9t + t2)) = 0

Combine like terms: 9t + -9t = 0
(-81 + 0 + t2) = 0
(-81 + t2) = 0

Solving
-81 + t2 = 0

Solving for variable 't'.

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

Add '81' to each side of the equation.
-81 + 81 + t2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + t2 = 0 + 81
t2 = 0 + 81

Combine like terms: 0 + 81 = 81
t2 = 81

Simplifying
t2 = 81

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