x^2+13x+9=0

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Solution for x^2+13x+9=0 equation:


Simplifying
x2 + 13x + 9 = 0

Reorder the terms:
9 + 13x + x2 = 0

Solving
9 + 13x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-9' to each side of the equation.
9 + 13x + -9 + x2 = 0 + -9

Reorder the terms:
9 + -9 + 13x + x2 = 0 + -9

Combine like terms: 9 + -9 = 0
0 + 13x + x2 = 0 + -9
13x + x2 = 0 + -9

Combine like terms: 0 + -9 = -9
13x + x2 = -9

The x term is 13x.  Take half its coefficient (6.5).
Square it (42.25) and add it to both sides.

Add '42.25' to each side of the equation.
13x + 42.25 + x2 = -9 + 42.25

Reorder the terms:
42.25 + 13x + x2 = -9 + 42.25

Combine like terms: -9 + 42.25 = 33.25
42.25 + 13x + x2 = 33.25

Factor a perfect square on the left side:
(x + 6.5)(x + 6.5) = 33.25

Calculate the square root of the right side: 5.766281297

Break this problem into two subproblems by setting 
(x + 6.5) equal to 5.766281297 and -5.766281297.

Subproblem 1

x + 6.5 = 5.766281297 Simplifying x + 6.5 = 5.766281297 Reorder the terms: 6.5 + x = 5.766281297 Solving 6.5 + x = 5.766281297 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-6.5' to each side of the equation. 6.5 + -6.5 + x = 5.766281297 + -6.5 Combine like terms: 6.5 + -6.5 = 0.0 0.0 + x = 5.766281297 + -6.5 x = 5.766281297 + -6.5 Combine like terms: 5.766281297 + -6.5 = -0.733718703 x = -0.733718703 Simplifying x = -0.733718703

Subproblem 2

x + 6.5 = -5.766281297 Simplifying x + 6.5 = -5.766281297 Reorder the terms: 6.5 + x = -5.766281297 Solving 6.5 + x = -5.766281297 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-6.5' to each side of the equation. 6.5 + -6.5 + x = -5.766281297 + -6.5 Combine like terms: 6.5 + -6.5 = 0.0 0.0 + x = -5.766281297 + -6.5 x = -5.766281297 + -6.5 Combine like terms: -5.766281297 + -6.5 = -12.266281297 x = -12.266281297 Simplifying x = -12.266281297

Solution

The solution to the problem is based on the solutions from the subproblems. x = {-0.733718703, -12.266281297}

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