(x+5)(2x-4)=2+16

Solution for (x+5)(2x-4)=2+16 equation:

Simplifying
(x + 5)(2x + -4) = 2 + 16

Reorder the terms:
(5 + x)(2x + -4) = 2 + 16

Reorder the terms:
(5 + x)(-4 + 2x) = 2 + 16

Multiply (5 + x) * (-4 + 2x)
(5(-4 + 2x) + x(-4 + 2x)) = 2 + 16
((-4 * 5 + 2x * 5) + x(-4 + 2x)) = 2 + 16
((-20 + 10x) + x(-4 + 2x)) = 2 + 16
(-20 + 10x + (-4 * x + 2x * x)) = 2 + 16
(-20 + 10x + (-4x + 2x2)) = 2 + 16

Combine like terms: 10x + -4x = 6x
(-20 + 6x + 2x2) = 2 + 16

Combine like terms: 2 + 16 = 18
-20 + 6x + 2x2 = 18

Solving
-20 + 6x + 2x2 = 18

Solving for variable 'x'.

Reorder the terms:
-20 + -18 + 6x + 2x2 = 18 + -18

Combine like terms: -20 + -18 = -38
-38 + 6x + 2x2 = 18 + -18

Combine like terms: 18 + -18 = 0
-38 + 6x + 2x2 = 0

Factor out the Greatest Common Factor (GCF), '2'.
2(-19 + 3x + x2) = 0

Ignore the factor 2.
Subproblem 1
Set the factor '(-19 + 3x + x2)' equal to zero and attempt to solve:

Simplifying
-19 + 3x + x2 = 0

Solving
-19 + 3x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '19' to each side of the equation.
-19 + 3x + 19 + x2 = 0 + 19

Reorder the terms:
-19 + 19 + 3x + x2 = 0 + 19

Combine like terms: -19 + 19 = 0
0 + 3x + x2 = 0 + 19
3x + x2 = 0 + 19

Combine like terms: 0 + 19 = 19
3x + x2 = 19

The x term is 3x.  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.
3x + 2.25 + x2 = 19 + 2.25

Reorder the terms:
2.25 + 3x + x2 = 19 + 2.25

Combine like terms: 19 + 2.25 = 21.25
2.25 + 3x + x2 = 21.25

Factor a perfect square on the left side:
(x + 1.5)(x + 1.5) = 21.25

Calculate the square root of the right side: 4.609772229

Break this problem into two subproblems by setting 
(x + 1.5) equal to 4.609772229 and -4.609772229.

Subproblem 1
x + 1.5 = 4.609772229

Simplifying
x + 1.5 = 4.609772229

Reorder the terms:
1.5 + x = 4.609772229

Solving
1.5 + x = 4.609772229

Solving for variable 'x'.

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

Add '-1.5' to each side of the equation.
1.5 + -1.5 + x = 4.609772229 + -1.5

Combine like terms: 1.5 + -1.5 = 0.0
0.0 + x = 4.609772229 + -1.5
x = 4.609772229 + -1.5

Combine like terms: 4.609772229 + -1.5 = 3.109772229
x = 3.109772229

Simplifying
x = 3.109772229

Subproblem 2
x + 1.5 = -4.609772229

Simplifying
x + 1.5 = -4.609772229

Reorder the terms:
1.5 + x = -4.609772229

Solving
1.5 + x = -4.609772229

Solving for variable 'x'.

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

Add '-1.5' to each side of the equation.
1.5 + -1.5 + x = -4.609772229 + -1.5

Combine like terms: 1.5 + -1.5 = 0.0
0.0 + x = -4.609772229 + -1.5
x = -4.609772229 + -1.5

Combine like terms: -4.609772229 + -1.5 = -6.109772229
x = -6.109772229

Simplifying
x = -6.109772229

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {3.109772229, -6.109772229}
Solution
x = {3.109772229, -6.109772229}