(5u-7)(4-u)=0

Solution for (5u-7)(4-u)=0 equation:

Simplifying
(5u + -7)(4 + -1u) = 0

Reorder the terms:
(-7 + 5u)(4 + -1u) = 0

Multiply (-7 + 5u) * (4 + -1u)
(-7(4 + -1u) + 5u * (4 + -1u)) = 0
((4 * -7 + -1u * -7) + 5u * (4 + -1u)) = 0
((-28 + 7u) + 5u * (4 + -1u)) = 0
(-28 + 7u + (4 * 5u + -1u * 5u)) = 0
(-28 + 7u + (20u + -5u2)) = 0

Combine like terms: 7u + 20u = 27u
(-28 + 27u + -5u2) = 0

Solving
-28 + 27u + -5u2 = 0

Solving for variable 'u'.

Factor a trinomial.
(-4 + u)(7 + -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 '(7 + -5u)' equal to zero and attempt to solve:

Simplifying
7 + -5u = 0

Solving
7 + -5u = 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 + -5u = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -5u = 0 + -7
-5u = 0 + -7

Combine like terms: 0 + -7 = -7
-5u = -7

Divide each side by '-5'.
u = 1.4

Simplifying
u = 1.4
Solution
u = {4, 1.4}