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

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

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

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

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

Combine like terms: 5u + 9u = 14u
(9 + 14u + 5u2) = 0

Solving
9 + 14u + 5u2 = 0

Solving for variable 'u'.

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

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

Simplifying
9 + 5u = 0

Solving
9 + 5u = 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 + 5u = 0 + -9

Combine like terms: 9 + -9 = 0
0 + 5u = 0 + -9
5u = 0 + -9

Combine like terms: 0 + -9 = -9
5u = -9

Divide each side by '5'.
u = -1.8

Simplifying
u = -1.8
Subproblem 2
Set the factor '(1 + u)' equal to zero and attempt to solve:

Simplifying
1 + u = 0

Solving
1 + u = 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 + u = 0 + -1

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

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

Simplifying
u = -1
Solution
u = {-1.8, -1}