6=3n(n-5)

Solution for 6=3n(n-5) equation:

Simplifying
6 = 3n(n + -5)

Reorder the terms:
6 = 3n(-5 + n)
6 = (-5 * 3n + n * 3n)
6 = (-15n + 3n2)

Solving
6 = -15n + 3n2

Solving for variable 'n'.

Reorder the terms:
6 + 15n + -3n2 = -15n + 15n + 3n2 + -3n2

Combine like terms: -15n + 15n = 0
6 + 15n + -3n2 = 0 + 3n2 + -3n2
6 + 15n + -3n2 = 3n2 + -3n2

Combine like terms: 3n2 + -3n2 = 0
6 + 15n + -3n2 = 0

Factor out the Greatest Common Factor (GCF), '3'.
3(2 + 5n + -1n2) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(2 + 5n + -1n2)' equal to zero and attempt to solve:

Simplifying
2 + 5n + -1n2 = 0

Solving
2 + 5n + -1n2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-2 + -5n + n2 = 0

Move the constant term to the right:

Add '2' to each side of the equation.
-2 + -5n + 2 + n2 = 0 + 2

Reorder the terms:
-2 + 2 + -5n + n2 = 0 + 2

Combine like terms: -2 + 2 = 0
0 + -5n + n2 = 0 + 2
-5n + n2 = 0 + 2

Combine like terms: 0 + 2 = 2
-5n + n2 = 2

The n term is -5n.  Take half its coefficient (-2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
-5n + 6.25 + n2 = 2 + 6.25

Reorder the terms:
6.25 + -5n + n2 = 2 + 6.25

Combine like terms: 2 + 6.25 = 8.25
6.25 + -5n + n2 = 8.25

Factor a perfect square on the left side:
(n + -2.5)(n + -2.5) = 8.25

Calculate the square root of the right side: 2.872281323

Break this problem into two subproblems by setting 
(n + -2.5) equal to 2.872281323 and -2.872281323.

Subproblem 1
n + -2.5 = 2.872281323

Simplifying
n + -2.5 = 2.872281323

Reorder the terms:
-2.5 + n = 2.872281323

Solving
-2.5 + n = 2.872281323

Solving for variable 'n'.

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

Add '2.5' to each side of the equation.
-2.5 + 2.5 + n = 2.872281323 + 2.5

Combine like terms: -2.5 + 2.5 = 0.0
0.0 + n = 2.872281323 + 2.5
n = 2.872281323 + 2.5

Combine like terms: 2.872281323 + 2.5 = 5.372281323
n = 5.372281323

Simplifying
n = 5.372281323

Subproblem 2
n + -2.5 = -2.872281323

Simplifying
n + -2.5 = -2.872281323

Reorder the terms:
-2.5 + n = -2.872281323

Solving
-2.5 + n = -2.872281323

Solving for variable 'n'.

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

Add '2.5' to each side of the equation.
-2.5 + 2.5 + n = -2.872281323 + 2.5

Combine like terms: -2.5 + 2.5 = 0.0
0.0 + n = -2.872281323 + 2.5
n = -2.872281323 + 2.5

Combine like terms: -2.872281323 + 2.5 = -0.372281323
n = -0.372281323

Simplifying
n = -0.372281323

Solution
The solution to the problem is based on the solutions
from the subproblems.
n = {5.372281323, -0.372281323}
Solution
n = {5.372281323, -0.372281323}