(7-u)(2u+1)=0

Solution for (7-u)(2u+1)=0 equation:

Simplifying
(7 + -1u)(2u + 1) = 0

Reorder the terms:
(7 + -1u)(1 + 2u) = 0

Multiply (7 + -1u) * (1 + 2u)
(7(1 + 2u) + -1u * (1 + 2u)) = 0
((1 * 7 + 2u * 7) + -1u * (1 + 2u)) = 0
((7 + 14u) + -1u * (1 + 2u)) = 0
(7 + 14u + (1 * -1u + 2u * -1u)) = 0
(7 + 14u + (-1u + -2u2)) = 0

Combine like terms: 14u + -1u = 13u
(7 + 13u + -2u2) = 0

Solving
7 + 13u + -2u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(7 + -1u)(1 + 2u) = 0

Subproblem 1
Set the factor '(7 + -1u)' equal to zero and attempt to solve:

Simplifying
7 + -1u = 0

Solving
7 + -1u = 0

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

Add '-7' to each side of the equation.
7 + -7 + -1u = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -1u = 0 + -7
-1u = 0 + -7

Combine like terms: 0 + -7 = -7
-1u = -7

Divide each side by '-1'.
u = 7

Simplifying
u = 7
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 = {7, -0.5}