=a^2-9a-36

Solution for =a^2-9a-36 equation:

Simplifying
0 = a2 + -9a + -36

Reorder the terms:
0 = -36 + -9a + a2

Solving
0 = -36 + -9a + a2

Solving for variable 'a'.

Combine like terms: 0 + 36 = 36
36 + 9a + -1a2 = -36 + -9a + a2 + 36 + 9a + -1a2

Reorder the terms:
36 + 9a + -1a2 = -36 + 36 + -9a + 9a + a2 + -1a2

Combine like terms: -36 + 36 = 0
36 + 9a + -1a2 = 0 + -9a + 9a + a2 + -1a2
36 + 9a + -1a2 = -9a + 9a + a2 + -1a2

Combine like terms: -9a + 9a = 0
36 + 9a + -1a2 = 0 + a2 + -1a2
36 + 9a + -1a2 = a2 + -1a2

Combine like terms: a2 + -1a2 = 0
36 + 9a + -1a2 = 0

Factor a trinomial.
(12 + -1a)(3 + a) = 0

Subproblem 1
Set the factor '(12 + -1a)' equal to zero and attempt to solve:

Simplifying
12 + -1a = 0

Solving
12 + -1a = 0

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

Add '-12' to each side of the equation.
12 + -12 + -1a = 0 + -12

Combine like terms: 12 + -12 = 0
0 + -1a = 0 + -12
-1a = 0 + -12

Combine like terms: 0 + -12 = -12
-1a = -12

Divide each side by '-1'.
a = 12

Simplifying
a = 12
Subproblem 2
Set the factor '(3 + a)' equal to zero and attempt to solve:

Simplifying
3 + a = 0

Solving
3 + a = 0

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

Add '-3' to each side of the equation.
3 + -3 + a = 0 + -3

Combine like terms: 3 + -3 = 0
0 + a = 0 + -3
a = 0 + -3

Combine like terms: 0 + -3 = -3
a = -3

Simplifying
a = -3
Solution
a = {12, -3}