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

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

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

Multiply (4 + -5u) * (4 + 5u)
(4(4 + 5u) + -5u * (4 + 5u)) = 0
((4 * 4 + 5u * 4) + -5u * (4 + 5u)) = 0
((16 + 20u) + -5u * (4 + 5u)) = 0
(16 + 20u + (4 * -5u + 5u * -5u)) = 0
(16 + 20u + (-20u + -25u2)) = 0

Combine like terms: 20u + -20u = 0
(16 + 0 + -25u2) = 0
(16 + -25u2) = 0

Solving
16 + -25u2 = 0

Solving for variable 'u'.

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

Add '-16' to each side of the equation.
16 + -16 + -25u2 = 0 + -16

Combine like terms: 16 + -16 = 0
0 + -25u2 = 0 + -16
-25u2 = 0 + -16

Combine like terms: 0 + -16 = -16
-25u2 = -16

Divide each side by '-25'.
u2 = 0.64

Simplifying
u2 = 0.64

Take the square root of each side:
u = {-0.8, 0.8}