(3x^2+9x)+(6x-24)=

Solution for (3x^2+9x)+(6x-24)= equation:

Simplifying
(3x2 + 9x) + (6x + -24) = 0

Reorder the terms:
(9x + 3x2) + (6x + -24) = 0

Remove parenthesis around (9x + 3x2)
9x + 3x2 + (6x + -24) = 0

Reorder the terms:
9x + 3x2 + (-24 + 6x) = 0

Remove parenthesis around (-24 + 6x)
9x + 3x2 + -24 + 6x = 0

Reorder the terms:
-24 + 9x + 6x + 3x2 = 0

Combine like terms: 9x + 6x = 15x
-24 + 15x + 3x2 = 0

Solving
-24 + 15x + 3x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-8 + 5x + x2) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-8 + 5x + x2)' equal to zero and attempt to solve:

Simplifying
-8 + 5x + x2 = 0

Solving
-8 + 5x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '8' to each side of the equation.
-8 + 5x + 8 + x2 = 0 + 8

Reorder the terms:
-8 + 8 + 5x + x2 = 0 + 8

Combine like terms: -8 + 8 = 0
0 + 5x + x2 = 0 + 8
5x + x2 = 0 + 8

Combine like terms: 0 + 8 = 8
5x + x2 = 8

The x term is 5x.  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.
5x + 6.25 + x2 = 8 + 6.25

Reorder the terms:
6.25 + 5x + x2 = 8 + 6.25

Combine like terms: 8 + 6.25 = 14.25
6.25 + 5x + x2 = 14.25

Factor a perfect square on the left side:
(x + 2.5)(x + 2.5) = 14.25

Calculate the square root of the right side: 3.774917218

Break this problem into two subproblems by setting 
(x + 2.5) equal to 3.774917218 and -3.774917218.

Subproblem 1
x + 2.5 = 3.774917218

Simplifying
x + 2.5 = 3.774917218

Reorder the terms:
2.5 + x = 3.774917218

Solving
2.5 + x = 3.774917218

Solving for variable 'x'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + x = 3.774917218 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + x = 3.774917218 + -2.5
x = 3.774917218 + -2.5

Combine like terms: 3.774917218 + -2.5 = 1.274917218
x = 1.274917218

Simplifying
x = 1.274917218

Subproblem 2
x + 2.5 = -3.774917218

Simplifying
x + 2.5 = -3.774917218

Reorder the terms:
2.5 + x = -3.774917218

Solving
2.5 + x = -3.774917218

Solving for variable 'x'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + x = -3.774917218 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + x = -3.774917218 + -2.5
x = -3.774917218 + -2.5

Combine like terms: -3.774917218 + -2.5 = -6.274917218
x = -6.274917218

Simplifying
x = -6.274917218

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {1.274917218, -6.274917218}
Solution
x = {1.274917218, -6.274917218}