h^2+5h-155=0

Solution for h^2+5h-155=0 equation:

Simplifying
h2 + 5h + -155 = 0

Reorder the terms:
-155 + 5h + h2 = 0

Solving
-155 + 5h + h2 = 0

Solving for variable 'h'.

Begin completing the square.

Move the constant term to the right:

Add '155' to each side of the equation.
-155 + 5h + 155 + h2 = 0 + 155

Reorder the terms:
-155 + 155 + 5h + h2 = 0 + 155

Combine like terms: -155 + 155 = 0
0 + 5h + h2 = 0 + 155
5h + h2 = 0 + 155

Combine like terms: 0 + 155 = 155
5h + h2 = 155

The h term is 5h.  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.
5h + 6.25 + h2 = 155 + 6.25

Reorder the terms:
6.25 + 5h + h2 = 155 + 6.25

Combine like terms: 155 + 6.25 = 161.25
6.25 + 5h + h2 = 161.25

Factor a perfect square on the left side:
(h + 2.5)(h + 2.5) = 161.25

Calculate the square root of the right side: 12.698425099

Break this problem into two subproblems by setting 
(h + 2.5) equal to 12.698425099 and -12.698425099.

Subproblem 1
h + 2.5 = 12.698425099

Simplifying
h + 2.5 = 12.698425099

Reorder the terms:
2.5 + h = 12.698425099

Solving
2.5 + h = 12.698425099

Solving for variable 'h'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + h = 12.698425099 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + h = 12.698425099 + -2.5
h = 12.698425099 + -2.5

Combine like terms: 12.698425099 + -2.5 = 10.198425099
h = 10.198425099

Simplifying
h = 10.198425099

Subproblem 2
h + 2.5 = -12.698425099

Simplifying
h + 2.5 = -12.698425099

Reorder the terms:
2.5 + h = -12.698425099

Solving
2.5 + h = -12.698425099

Solving for variable 'h'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + h = -12.698425099 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + h = -12.698425099 + -2.5
h = -12.698425099 + -2.5

Combine like terms: -12.698425099 + -2.5 = -15.198425099
h = -15.198425099

Simplifying
h = -15.198425099

Solution
The solution to the problem is based on the solutions
from the subproblems.
h = {10.198425099, -15.198425099}