3(x+-6)(2.3x+-6)=800

Solution for 3(x+-6)(2.3x+-6)=800 equation:

Simplifying
3(x + -6)(2.3x + -6) = 800

Reorder the terms:
3(-6 + x)(2.3x + -6) = 800

Reorder the terms:
3(-6 + x)(-6 + 2.3x) = 800

Multiply (-6 + x) * (-6 + 2.3x)
3(-6(-6 + 2.3x) + x(-6 + 2.3x)) = 800
3((-6 * -6 + 2.3x * -6) + x(-6 + 2.3x)) = 800
3((36 + -13.8x) + x(-6 + 2.3x)) = 800
3(36 + -13.8x + (-6 * x + 2.3x * x)) = 800
3(36 + -13.8x + (-6x + 2.3x2)) = 800

Combine like terms: -13.8x + -6x = -19.8x
3(36 + -19.8x + 2.3x2) = 800
(36 * 3 + -19.8x * 3 + 2.3x2 * 3) = 800
(108 + -59.4x + 6.9x2) = 800

Solving
108 + -59.4x + 6.9x2 = 800

Solving for variable 'x'.

Reorder the terms:
108 + -800 + -59.4x + 6.9x2 = 800 + -800

Combine like terms: 108 + -800 = -692
-692 + -59.4x + 6.9x2 = 800 + -800

Combine like terms: 800 + -800 = 0
-692 + -59.4x + 6.9x2 = 0

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

Divide each side by '6.9'.
-100.2898551 + -8.608695652x + x2 = 0

Move the constant term to the right:

Add '100.2898551' to each side of the equation.
-100.2898551 + -8.608695652x + 100.2898551 + x2 = 0 + 100.2898551

Reorder the terms:
-100.2898551 + 100.2898551 + -8.608695652x + x2 = 0 + 100.2898551

Combine like terms: -100.2898551 + 100.2898551 = 0.0000000
0.0000000 + -8.608695652x + x2 = 0 + 100.2898551
-8.608695652x + x2 = 0 + 100.2898551

Combine like terms: 0 + 100.2898551 = 100.2898551
-8.608695652x + x2 = 100.2898551

The x term is -8.608695652x.  Take half its coefficient (-4.304347826).
Square it (18.52741021) and add it to both sides.

Add '18.52741021' to each side of the equation.
-8.608695652x + 18.52741021 + x2 = 100.2898551 + 18.52741021

Reorder the terms:
18.52741021 + -8.608695652x + x2 = 100.2898551 + 18.52741021

Combine like terms: 100.2898551 + 18.52741021 = 118.81726531
18.52741021 + -8.608695652x + x2 = 118.81726531

Factor a perfect square on the left side:
(x + -4.304347826)(x + -4.304347826) = 118.81726531

Calculate the square root of the right side: 10.900333266

Break this problem into two subproblems by setting 
(x + -4.304347826) equal to 10.900333266 and -10.900333266.

Subproblem 1
x + -4.304347826 = 10.900333266

Simplifying
x + -4.304347826 = 10.900333266

Reorder the terms:
-4.304347826 + x = 10.900333266

Solving
-4.304347826 + x = 10.900333266

Solving for variable 'x'.

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

Add '4.304347826' to each side of the equation.
-4.304347826 + 4.304347826 + x = 10.900333266 + 4.304347826

Combine like terms: -4.304347826 + 4.304347826 = 0.000000000
0.000000000 + x = 10.900333266 + 4.304347826
x = 10.900333266 + 4.304347826

Combine like terms: 10.900333266 + 4.304347826 = 15.204681092
x = 15.204681092

Simplifying
x = 15.204681092

Subproblem 2
x + -4.304347826 = -10.900333266

Simplifying
x + -4.304347826 = -10.900333266

Reorder the terms:
-4.304347826 + x = -10.900333266

Solving
-4.304347826 + x = -10.900333266

Solving for variable 'x'.

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

Add '4.304347826' to each side of the equation.
-4.304347826 + 4.304347826 + x = -10.900333266 + 4.304347826

Combine like terms: -4.304347826 + 4.304347826 = 0.000000000
0.000000000 + x = -10.900333266 + 4.304347826
x = -10.900333266 + 4.304347826

Combine like terms: -10.900333266 + 4.304347826 = -6.59598544
x = -6.59598544

Simplifying
x = -6.59598544

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {15.204681092, -6.59598544}