(x+9)(x+3)=0

Solution for (x+9)(x+3)=0 equation:

Simplifying
(x + 9)(x + 3) = 0

Reorder the terms:
(9 + x)(x + 3) = 0

Reorder the terms:
(9 + x)(3 + x) = 0

Multiply (9 + x) * (3 + x)
(9(3 + x) + x(3 + x)) = 0
((3 * 9 + x * 9) + x(3 + x)) = 0
((27 + 9x) + x(3 + x)) = 0
(27 + 9x + (3 * x + x * x)) = 0
(27 + 9x + (3x + x2)) = 0

Combine like terms: 9x + 3x = 12x
(27 + 12x + x2) = 0

Solving
27 + 12x + x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(9 + x)(3 + x) = 0

Subproblem 1
Set the factor '(9 + x)' equal to zero and attempt to solve:

Simplifying
9 + x = 0

Solving
9 + x = 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 + x = 0 + -9

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

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

Simplifying
x = -9
Subproblem 2
Set the factor '(3 + x)' equal to zero and attempt to solve:

Simplifying
3 + x = 0

Solving
3 + x = 0

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

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

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

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

Simplifying
x = -3
Solution
x = {-9, -3}