(x-9)(x+4)=

Solution for (x-9)(x+4)= equation:

Simplifying
(x + -9)(x + 4) = 0

Reorder the terms:
(-9 + x)(x + 4) = 0

Reorder the terms:
(-9 + x)(4 + x) = 0

Multiply (-9 + x) * (4 + x)
(-9(4 + x) + x(4 + x)) = 0
((4 * -9 + x * -9) + x(4 + x)) = 0
((-36 + -9x) + x(4 + x)) = 0
(-36 + -9x + (4 * x + x * x)) = 0
(-36 + -9x + (4x + x2)) = 0

Combine like terms: -9x + 4x = -5x
(-36 + -5x + x2) = 0

Solving
-36 + -5x + x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(-4 + -1x)(9 + -1x) = 0

Subproblem 1
Set the factor '(-4 + -1x)' equal to zero and attempt to solve:

Simplifying
-4 + -1x = 0

Solving
-4 + -1x = 0

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

Add '4' to each side of the equation.
-4 + 4 + -1x = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -1x = 0 + 4
-1x = 0 + 4

Combine like terms: 0 + 4 = 4
-1x = 4

Divide each side by '-1'.
x = -4

Simplifying
x = -4
Subproblem 2
Set the factor '(9 + -1x)' equal to zero and attempt to solve:

Simplifying
9 + -1x = 0

Solving
9 + -1x = 0

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

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

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

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

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

Simplifying
x = 9
Solution
x = {-4, 9}