(4+u)(5u+3)=0

Solution for (4+u)(5u+3)=0 equation:

Simplifying
(4 + u)(5u + 3) = 0

Reorder the terms:
(4 + u)(3 + 5u) = 0

Multiply (4 + u) * (3 + 5u)
(4(3 + 5u) + u(3 + 5u)) = 0
((3 * 4 + 5u * 4) + u(3 + 5u)) = 0
((12 + 20u) + u(3 + 5u)) = 0
(12 + 20u + (3 * u + 5u * u)) = 0
(12 + 20u + (3u + 5u2)) = 0

Combine like terms: 20u + 3u = 23u
(12 + 23u + 5u2) = 0

Solving
12 + 23u + 5u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(4 + u)(3 + 5u) = 0

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

Simplifying
4 + u = 0

Solving
4 + u = 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 + u = 0 + -4

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

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

Simplifying
u = -4
Subproblem 2
Set the factor '(3 + 5u)' equal to zero and attempt to solve:

Simplifying
3 + 5u = 0

Solving
3 + 5u = 0

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

Add '-3' to each side of the equation.
3 + -3 + 5u = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 5u = 0 + -3
5u = 0 + -3

Combine like terms: 0 + -3 = -3
5u = -3

Divide each side by '5'.
u = -0.6

Simplifying
u = -0.6
Solution
u = {-4, -0.6}