-3x(x+5)=-18

Solution for -3x(x+5)=-18 equation:

Simplifying
-3x(x + 5) = -18

Reorder the terms:
-3x(5 + x) = -18
(5 * -3x + x * -3x) = -18
(-15x + -3x2) = -18

Solving
-15x + -3x2 = -18

Solving for variable 'x'.

Reorder the terms:
18 + -15x + -3x2 = -18 + 18

Combine like terms: -18 + 18 = 0
18 + -15x + -3x2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(6 + -5x + -1x2) = 0

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

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

Simplifying
1 + -1x = 0

Solving
1 + -1x = 0

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

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

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

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

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

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

Simplifying
6 + x = 0

Solving
6 + x = 0

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

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

Combine like terms: 6 + -6 = 0
0 + x = 0 + -6
x = 0 + -6

Combine like terms: 0 + -6 = -6
x = -6

Simplifying
x = -6
Solution
x = {1, -6}