(a+9)(a-5)=

Solution for (a+9)(a-5)= equation:

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

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

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

Multiply (9 + a) * (-5 + a)
(9(-5 + a) + a(-5 + a)) = 0
((-5 * 9 + a * 9) + a(-5 + a)) = 0
((-45 + 9a) + a(-5 + a)) = 0
(-45 + 9a + (-5 * a + a * a)) = 0
(-45 + 9a + (-5a + a2)) = 0

Combine like terms: 9a + -5a = 4a
(-45 + 4a + a2) = 0

Solving
-45 + 4a + a2 = 0

Solving for variable 'a'.

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

Subproblem 1
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
Subproblem 2
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
Solution
a = {-9, 5}