0=(-u^2)-(5u)+144

Solution for 0=(-u^2)-(5u)+144 equation:

Simplifying
0 = (-1u2) + -1(5u) + 144

Remove parenthesis around (5u)
0 = (-1u2) + -1 * 5u + 144

Multiply -1 * 5
0 = (-1u2) + -5u + 144

Reorder the terms:
0 = 144 + -5u + (-1u2)

Solving
0 = 144 + -5u + (-1u2)

Solving for variable 'u'.
0 + -144 + 5u + u2 = 144 + -5u + (-1u2) + -144 + 5u + (u2)

Combine like terms: 0 + -144 = -144
-144 + 5u + u2 = 144 + -5u + (-1u2) + -144 + 5u + (u2)
-144 + 5u + u2 = 144 + -5u + (-1u2) + -144 + 5u + u2

Reorder the terms:
-144 + 5u + u2 = 144 + -144 + -5u + 5u + (-1u2) + u2

Combine like terms: 144 + -144 = 0
-144 + 5u + u2 = 0 + -5u + 5u + (-1u2) + u2
-144 + 5u + u2 = -5u + 5u + (-1u2) + u2

Combine like terms: -5u + 5u = 0
-144 + 5u + u2 = 0 + (-1u2) + u2
-144 + 5u + u2 = (-1u2) + u2

Combine like terms: (-1u2) + u2 = 0
-144 + 5u + u2 = 0

Begin completing the square.

Move the constant term to the right:

Add '144' to each side of the equation.
-144 + 5u + 144 + u2 = 0 + 144

Reorder the terms:
-144 + 144 + 5u + u2 = 0 + 144

Combine like terms: -144 + 144 = 0
0 + 5u + u2 = 0 + 144
5u + u2 = 0 + 144

Combine like terms: 0 + 144 = 144
5u + u2 = 144

The u term is 5u.  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.
5u + 6.25 + u2 = 144 + 6.25

Reorder the terms:
6.25 + 5u + u2 = 144 + 6.25

Combine like terms: 144 + 6.25 = 150.25
6.25 + 5u + u2 = 150.25

Factor a perfect square on the left side:
(u + 2.5)(u + 2.5) = 150.25

Calculate the square root of the right side: 12.257650672

Break this problem into two subproblems by setting 
(u + 2.5) equal to 12.257650672 and -12.257650672.

Subproblem 1
u + 2.5 = 12.257650672

Simplifying
u + 2.5 = 12.257650672

Reorder the terms:
2.5 + u = 12.257650672

Solving
2.5 + u = 12.257650672

Solving for variable 'u'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + u = 12.257650672 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + u = 12.257650672 + -2.5
u = 12.257650672 + -2.5

Combine like terms: 12.257650672 + -2.5 = 9.757650672
u = 9.757650672

Simplifying
u = 9.757650672

Subproblem 2
u + 2.5 = -12.257650672

Simplifying
u + 2.5 = -12.257650672

Reorder the terms:
2.5 + u = -12.257650672

Solving
2.5 + u = -12.257650672

Solving for variable 'u'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + u = -12.257650672 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + u = -12.257650672 + -2.5
u = -12.257650672 + -2.5

Combine like terms: -12.257650672 + -2.5 = -14.757650672
u = -14.757650672

Simplifying
u = -14.757650672

Solution
The solution to the problem is based on the solutions
from the subproblems.
u = {9.757650672, -14.757650672}