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

Solution for (3-u)(5u+1)=0 equation:

Simplifying
(3 + -1u)(5u + 1) = 0

Reorder the terms:
(3 + -1u)(1 + 5u) = 0

Multiply (3 + -1u) * (1 + 5u)
(3(1 + 5u) + -1u * (1 + 5u)) = 0
((1 * 3 + 5u * 3) + -1u * (1 + 5u)) = 0
((3 + 15u) + -1u * (1 + 5u)) = 0
(3 + 15u + (1 * -1u + 5u * -1u)) = 0
(3 + 15u + (-1u + -5u2)) = 0

Combine like terms: 15u + -1u = 14u
(3 + 14u + -5u2) = 0

Solving
3 + 14u + -5u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(3 + -1u)(1 + 5u) = 0

Subproblem 1
Set the factor '(3 + -1u)' equal to zero and attempt to solve:

Simplifying
3 + -1u = 0

Solving
3 + -1u = 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 + -1u = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1u = 0 + -3
-1u = 0 + -3

Combine like terms: 0 + -3 = -3
-1u = -3

Divide each side by '-1'.
u = 3

Simplifying
u = 3
Subproblem 2
Set the factor '(1 + 5u)' equal to zero and attempt to solve:

Simplifying
1 + 5u = 0

Solving
1 + 5u = 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 + 5u = 0 + -1

Combine like terms: 1 + -1 = 0
0 + 5u = 0 + -1
5u = 0 + -1

Combine like terms: 0 + -1 = -1
5u = -1

Divide each side by '5'.
u = -0.2

Simplifying
u = -0.2
Solution
u = {3, -0.2}