12=6(y-3)(y)

Solution for 12=6(y-3)(y) equation:

Simplifying
12 = 6(y + -3)(y)

Reorder the terms:
12 = 6(-3 + y)(y)

Reorder the terms for easier multiplication:
12 = 6y(-3 + y)
12 = (-3 * 6y + y * 6y)
12 = (-18y + 6y2)

Solving
12 = -18y + 6y2

Solving for variable 'y'.

Reorder the terms:
12 + 18y + -6y2 = -18y + 18y + 6y2 + -6y2

Combine like terms: -18y + 18y = 0
12 + 18y + -6y2 = 0 + 6y2 + -6y2
12 + 18y + -6y2 = 6y2 + -6y2

Combine like terms: 6y2 + -6y2 = 0
12 + 18y + -6y2 = 0

Factor out the Greatest Common Factor (GCF), '6'.
6(2 + 3y + -1y2) = 0

Ignore the factor 6.
Subproblem 1
Set the factor '(2 + 3y + -1y2)' equal to zero and attempt to solve:

Simplifying
2 + 3y + -1y2 = 0

Solving
2 + 3y + -1y2 = 0

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

Divide each side by '-1'.
-2 + -3y + y2 = 0

Move the constant term to the right:

Add '2' to each side of the equation.
-2 + -3y + 2 + y2 = 0 + 2

Reorder the terms:
-2 + 2 + -3y + y2 = 0 + 2

Combine like terms: -2 + 2 = 0
0 + -3y + y2 = 0 + 2
-3y + y2 = 0 + 2

Combine like terms: 0 + 2 = 2
-3y + y2 = 2

The y term is -3y.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3y + 2.25 + y2 = 2 + 2.25

Reorder the terms:
2.25 + -3y + y2 = 2 + 2.25

Combine like terms: 2 + 2.25 = 4.25
2.25 + -3y + y2 = 4.25

Factor a perfect square on the left side:
(y + -1.5)(y + -1.5) = 4.25

Calculate the square root of the right side: 2.061552813

Break this problem into two subproblems by setting 
(y + -1.5) equal to 2.061552813 and -2.061552813.

Subproblem 1
y + -1.5 = 2.061552813

Simplifying
y + -1.5 = 2.061552813

Reorder the terms:
-1.5 + y = 2.061552813

Solving
-1.5 + y = 2.061552813

Solving for variable 'y'.

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

Add '1.5' to each side of the equation.
-1.5 + 1.5 + y = 2.061552813 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + y = 2.061552813 + 1.5
y = 2.061552813 + 1.5

Combine like terms: 2.061552813 + 1.5 = 3.561552813
y = 3.561552813

Simplifying
y = 3.561552813

Subproblem 2
y + -1.5 = -2.061552813

Simplifying
y + -1.5 = -2.061552813

Reorder the terms:
-1.5 + y = -2.061552813

Solving
-1.5 + y = -2.061552813

Solving for variable 'y'.

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

Add '1.5' to each side of the equation.
-1.5 + 1.5 + y = -2.061552813 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + y = -2.061552813 + 1.5
y = -2.061552813 + 1.5

Combine like terms: -2.061552813 + 1.5 = -0.561552813
y = -0.561552813

Simplifying
y = -0.561552813

Solution
The solution to the problem is based on the solutions
from the subproblems.
y = {3.561552813, -0.561552813}
Solution
y = {3.561552813, -0.561552813}