(-h+9)(-h-9)=

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

Simplifying
(-1h + 9)(-1h + -9) = 0

Reorder the terms:
(9 + -1h)(-1h + -9) = 0

Reorder the terms:
(9 + -1h)(-9 + -1h) = 0

Multiply (9 + -1h) * (-9 + -1h)
(9(-9 + -1h) + -1h * (-9 + -1h)) = 0
((-9 * 9 + -1h * 9) + -1h * (-9 + -1h)) = 0
((-81 + -9h) + -1h * (-9 + -1h)) = 0
(-81 + -9h + (-9 * -1h + -1h * -1h)) = 0
(-81 + -9h + (9h + 1h2)) = 0

Combine like terms: -9h + 9h = 0
(-81 + 0 + 1h2) = 0
(-81 + 1h2) = 0

Solving
-81 + 1h2 = 0

Solving for variable 'h'.

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

Add '81' to each side of the equation.
-81 + 81 + 1h2 = 0 + 81

Combine like terms: -81 + 81 = 0
0 + 1h2 = 0 + 81
1h2 = 0 + 81

Combine like terms: 0 + 81 = 81
1h2 = 81

Divide each side by '1'.
h2 = 81

Simplifying
h2 = 81

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