(A+5)(A-9)=0

Solution for (A+5)(A-9)=0 equation:

Simplifying
(A + 5)(A + -9) = 0

Reorder the terms:
(5 + A)(A + -9) = 0

Reorder the terms:
(5 + A)(-9 + A) = 0

Multiply (5 + A) * (-9 + A)
(5(-9 + A) + A(-9 + A)) = 0
((-9 * 5 + A * 5) + A(-9 + A)) = 0
((-45 + 5A) + A(-9 + A)) = 0
(-45 + 5A + (-9 * A + A * A)) = 0
(-45 + 5A + (-9A + A2)) = 0

Combine like terms: 5A + -9A = -4A
(-45 + -4A + A2) = 0

Solving
-45 + -4A + A2 = 0

Solving for variable 'A'.

Factor a trinomial.
(-5 + -1A)(9 + -1A) = 0

Subproblem 1
Set the factor '(-5 + -1A)' equal to zero and attempt to solve:

Simplifying
-5 + -1A = 0

Solving
-5 + -1A = 0

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

Add '5' to each side of the equation.
-5 + 5 + -1A = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1A = 0 + 5
-1A = 0 + 5

Combine like terms: 0 + 5 = 5
-1A = 5

Divide each side by '-1'.
A = -5

Simplifying
A = -5
Subproblem 2
Set the factor '(9 + -1A)' equal to zero and attempt to solve:

Simplifying
9 + -1A = 0

Solving
9 + -1A = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1A = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1A = 0 + -9
-1A = 0 + -9

Combine like terms: 0 + -9 = -9
-1A = -9

Divide each side by '-1'.
A = 9

Simplifying
A = 9
Solution
A = {-5, 9}