x^2+13x+42.25=0

Solution for x^2+13x+42.25=0 equation:

Simplifying
x2 + 13x + 42.25 = 0

Reorder the terms:
42.25 + 13x + x2 = 0

Solving
42.25 + 13x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-42.25' to each side of the equation.
42.25 + 13x + -42.25 + x2 = 0 + -42.25

Reorder the terms:
42.25 + -42.25 + 13x + x2 = 0 + -42.25

Combine like terms: 42.25 + -42.25 = 0.00
0.00 + 13x + x2 = 0 + -42.25
13x + x2 = 0 + -42.25

Combine like terms: 0 + -42.25 = -42.25
13x + x2 = -42.25

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 = -42.25 + 42.25

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

Combine like terms: -42.25 + 42.25 = 0.00
42.25 + 13x + x2 = 0.00

Factor a perfect square on the left side:
(x + 6.5)(x + 6.5) = 0.00

Calculate the square root of the right side: 0.00

Break this problem into two subproblems by setting 
(x + 6.5) equal to 0.00 and 0.00.

Subproblem 1
x + 6.5 = 0.00

Simplifying
x + 6.5 = 0.00

Reorder the terms:
6.5 + x = 0.00

Solving
6.5 + x = 0.00

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 = 0.00 + -6.5

Combine like terms: 6.5 + -6.5 = 0.0
0.0 + x = 0.00 + -6.5
x = 0.00 + -6.5

Combine like terms: 0.00 + -6.5 = -6.5
x = -6.5

Simplifying
x = -6.5

Subproblem 2
x + 6.5 = 0.00

Simplifying
x + 6.5 = 0.00

Reorder the terms:
6.5 + x = 0.00

Solving
6.5 + x = 0.00

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 = 0.00 + -6.5

Combine like terms: 6.5 + -6.5 = 0.0
0.0 + x = 0.00 + -6.5
x = 0.00 + -6.5

Combine like terms: 0.00 + -6.5 = -6.5
x = -6.5

Simplifying
x = -6.5

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {-6.5, -6.5}