(2u+1)(9+u)=0

Solution for (2u+1)(9+u)=0 equation:

Simplifying
(2u + 1)(9 + u) = 0

Reorder the terms:
(1 + 2u)(9 + u) = 0

Multiply (1 + 2u) * (9 + u)
(1(9 + u) + 2u * (9 + u)) = 0
((9 * 1 + u * 1) + 2u * (9 + u)) = 0
((9 + 1u) + 2u * (9 + u)) = 0
(9 + 1u + (9 * 2u + u * 2u)) = 0
(9 + 1u + (18u + 2u2)) = 0

Combine like terms: 1u + 18u = 19u
(9 + 19u + 2u2) = 0

Solving
9 + 19u + 2u2 = 0

Solving for variable 'u'.

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

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

Simplifying
9 + u = 0

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

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

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

Simplifying
u = -9
Subproblem 2
Set the factor '(1 + 2u)' equal to zero and attempt to solve:

Simplifying
1 + 2u = 0

Solving
1 + 2u = 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 + 2u = 0 + -1

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

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

Divide each side by '2'.
u = -0.5

Simplifying
u = -0.5
Solution
u = {-9, -0.5}