(q+9)(q-3)=0

Solution for (q+9)(q-3)=0 equation:

Simplifying
(q + 9)(q + -3) = 0

Reorder the terms:
(9 + q)(q + -3) = 0

Reorder the terms:
(9 + q)(-3 + q) = 0

Multiply (9 + q) * (-3 + q)
(9(-3 + q) + q(-3 + q)) = 0
((-3 * 9 + q * 9) + q(-3 + q)) = 0
((-27 + 9q) + q(-3 + q)) = 0
(-27 + 9q + (-3 * q + q * q)) = 0
(-27 + 9q + (-3q + q2)) = 0

Combine like terms: 9q + -3q = 6q
(-27 + 6q + q2) = 0

Solving
-27 + 6q + q2 = 0

Solving for variable 'q'.

Factor a trinomial.
(-9 + -1q)(3 + -1q) = 0

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

Simplifying
-9 + -1q = 0

Solving
-9 + -1q = 0

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

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

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

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

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

Simplifying
q = -9
Subproblem 2
Set the factor '(3 + -1q)' equal to zero and attempt to solve:

Simplifying
3 + -1q = 0

Solving
3 + -1q = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1q = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1q = 0 + -3
-1q = 0 + -3

Combine like terms: 0 + -3 = -3
-1q = -3

Divide each side by '-1'.
q = 3

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