n^2-(3*n+18)=0

Solution for n^2-(3*n+18)=0 equation:

Simplifying
n2 + -1(3n + 18) = 0

Reorder the terms:
n2 + -1(18 + 3n) = 0
n2 + (18 * -1 + 3n * -1) = 0
n2 + (-18 + -3n) = 0

Reorder the terms:
-18 + -3n + n2 = 0

Solving
-18 + -3n + n2 = 0

Solving for variable 'n'.

Factor a trinomial.
(-3 + -1n)(6 + -1n) = 0

Subproblem 1
Set the factor '(-3 + -1n)' equal to zero and attempt to solve:

Simplifying
-3 + -1n = 0

Solving
-3 + -1n = 0

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

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

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

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

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

Simplifying
n = -3
Subproblem 2
Set the factor '(6 + -1n)' equal to zero and attempt to solve:

Simplifying
6 + -1n = 0

Solving
6 + -1n = 0

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

Add '-6' to each side of the equation.
6 + -6 + -1n = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -1n = 0 + -6
-1n = 0 + -6

Combine like terms: 0 + -6 = -6
-1n = -6

Divide each side by '-1'.
n = 6

Simplifying
n = 6
Solution
n = {-3, 6}