-5(u+9)(-u+1)=0

Solution for -5(u+9)(-u+1)=0 equation:

Simplifying
-5(u + 9)(-1u + 1) = 0

Reorder the terms:
-5(9 + u)(-1u + 1) = 0

Reorder the terms:
-5(9 + u)(1 + -1u) = 0

Multiply (9 + u) * (1 + -1u)
-5(9(1 + -1u) + u(1 + -1u)) = 0
-5((1 * 9 + -1u * 9) + u(1 + -1u)) = 0
-5((9 + -9u) + u(1 + -1u)) = 0
-5(9 + -9u + (1 * u + -1u * u)) = 0
-5(9 + -9u + (1u + -1u2)) = 0

Combine like terms: -9u + 1u = -8u
-5(9 + -8u + -1u2) = 0
(9 * -5 + -8u * -5 + -1u2 * -5) = 0
(-45 + 40u + 5u2) = 0

Solving
-45 + 40u + 5u2 = 0

Solving for variable 'u'.

Factor out the Greatest Common Factor (GCF), '5'.
5(-9 + 8u + u2) = 0

Factor a trinomial.
5((-9 + -1u)(1 + -1u)) = 0

Ignore the factor 5.
Subproblem 1
Set the factor '(-9 + -1u)' equal to zero and attempt to solve:

Simplifying
-9 + -1u = 0

Solving
-9 + -1u = 0

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

Add '9' to each side of the equation.
-9 + 9 + -1u = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -1u = 0 + 9
-1u = 0 + 9

Combine like terms: 0 + 9 = 9
-1u = 9

Divide each side by '-1'.
u = -9

Simplifying
u = -9
Subproblem 2
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
Solution
u = {-9, 1}