u^2-(2u)-8=0

Solution for u^2-(2u)-8=0 equation:

Simplifying
u2 + -1(2u) + -8 = 0

Remove parenthesis around (2u)
u2 + -1 * 2u + -8 = 0

Multiply -1 * 2
u2 + -2u + -8 = 0

Reorder the terms:
-8 + -2u + u2 = 0

Solving
-8 + -2u + u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(-2 + -1u)(4 + -1u) = 0

Subproblem 1
Set the factor '(-2 + -1u)' equal to zero and attempt to solve:

Simplifying
-2 + -1u = 0

Solving
-2 + -1u = 0

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

Add '2' to each side of the equation.
-2 + 2 + -1u = 0 + 2

Combine like terms: -2 + 2 = 0
0 + -1u = 0 + 2
-1u = 0 + 2

Combine like terms: 0 + 2 = 2
-1u = 2

Divide each side by '-1'.
u = -2

Simplifying
u = -2
Subproblem 2
Set the factor '(4 + -1u)' equal to zero and attempt to solve:

Simplifying
4 + -1u = 0

Solving
4 + -1u = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1u = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1u = 0 + -4
-1u = 0 + -4

Combine like terms: 0 + -4 = -4
-1u = -4

Divide each side by '-1'.
u = 4

Simplifying
u = 4
Solution
u = {-2, 4}