3m(m+4)=18

Solution for 3m(m+4)=18 equation:

Simplifying
3m(m + 4) = 18

Reorder the terms:
3m(4 + m) = 18
(4 * 3m + m * 3m) = 18
(12m + 3m2) = 18

Solving
12m + 3m2 = 18

Solving for variable 'm'.

Reorder the terms:
-18 + 12m + 3m2 = 18 + -18

Combine like terms: 18 + -18 = 0
-18 + 12m + 3m2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(-6 + 4m + m2) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-6 + 4m + m2)' equal to zero and attempt to solve:

Simplifying
-6 + 4m + m2 = 0

Solving
-6 + 4m + m2 = 0

Begin completing the square.

Move the constant term to the right:

Add '6' to each side of the equation.
-6 + 4m + 6 + m2 = 0 + 6

Reorder the terms:
-6 + 6 + 4m + m2 = 0 + 6

Combine like terms: -6 + 6 = 0
0 + 4m + m2 = 0 + 6
4m + m2 = 0 + 6

Combine like terms: 0 + 6 = 6
4m + m2 = 6

The m term is 4m.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4m + 4 + m2 = 6 + 4

Reorder the terms:
4 + 4m + m2 = 6 + 4

Combine like terms: 6 + 4 = 10
4 + 4m + m2 = 10

Factor a perfect square on the left side:
(m + 2)(m + 2) = 10

Calculate the square root of the right side: 3.16227766

Break this problem into two subproblems by setting 
(m + 2) equal to 3.16227766 and -3.16227766.

Subproblem 1
m + 2 = 3.16227766

Simplifying
m + 2 = 3.16227766

Reorder the terms:
2 + m = 3.16227766

Solving
2 + m = 3.16227766

Solving for variable 'm'.

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

Add '-2' to each side of the equation.
2 + -2 + m = 3.16227766 + -2

Combine like terms: 2 + -2 = 0
0 + m = 3.16227766 + -2
m = 3.16227766 + -2

Combine like terms: 3.16227766 + -2 = 1.16227766
m = 1.16227766

Simplifying
m = 1.16227766

Subproblem 2
m + 2 = -3.16227766

Simplifying
m + 2 = -3.16227766

Reorder the terms:
2 + m = -3.16227766

Solving
2 + m = -3.16227766

Solving for variable 'm'.

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

Add '-2' to each side of the equation.
2 + -2 + m = -3.16227766 + -2

Combine like terms: 2 + -2 = 0
0 + m = -3.16227766 + -2
m = -3.16227766 + -2

Combine like terms: -3.16227766 + -2 = -5.16227766
m = -5.16227766

Simplifying
m = -5.16227766

Solution
The solution to the problem is based on the solutions
from the subproblems.
m = {1.16227766, -5.16227766}
Solution
m = {1.16227766, -5.16227766}