(u-8)(u+1)=0

Solution for (u-8)(u+1)=0 equation:

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

Reorder the terms:
(-8 + u)(u + 1) = 0

Reorder the terms:
(-8 + u)(1 + u) = 0

Multiply (-8 + u) * (1 + u)
(-8(1 + u) + u(1 + u)) = 0
((1 * -8 + u * -8) + u(1 + u)) = 0
((-8 + -8u) + u(1 + u)) = 0
(-8 + -8u + (1 * u + u * u)) = 0
(-8 + -8u + (1u + u2)) = 0

Combine like terms: -8u + 1u = -7u
(-8 + -7u + u2) = 0

Solving
-8 + -7u + u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(-1 + -1u)(8 + -1u) = 0

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

Simplifying
-1 + -1u = 0

Solving
-1 + -1u = 0

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

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

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

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

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

Simplifying
u = -1
Subproblem 2
Set the factor '(8 + -1u)' equal to zero and attempt to solve:

Simplifying
8 + -1u = 0

Solving
8 + -1u = 0

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

Add '-8' to each side of the equation.
8 + -8 + -1u = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -1u = 0 + -8
-1u = 0 + -8

Combine like terms: 0 + -8 = -8
-1u = -8

Divide each side by '-1'.
u = 8

Simplifying
u = 8
Solution
u = {-1, 8}