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

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

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

Reorder the terms:
(-4 + -5x)(-5x + 4) = 0

Reorder the terms:
(-4 + -5x)(4 + -5x) = 0

Multiply (-4 + -5x) * (4 + -5x)
(-4(4 + -5x) + -5x * (4 + -5x)) = 0
((4 * -4 + -5x * -4) + -5x * (4 + -5x)) = 0
((-16 + 20x) + -5x * (4 + -5x)) = 0
(-16 + 20x + (4 * -5x + -5x * -5x)) = 0
(-16 + 20x + (-20x + 25x2)) = 0

Combine like terms: 20x + -20x = 0
(-16 + 0 + 25x2) = 0
(-16 + 25x2) = 0

Solving
-16 + 25x2 = 0

Solving for variable 'x'.

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

Add '16' to each side of the equation.
-16 + 16 + 25x2 = 0 + 16

Combine like terms: -16 + 16 = 0
0 + 25x2 = 0 + 16
25x2 = 0 + 16

Combine like terms: 0 + 16 = 16
25x2 = 16

Divide each side by '25'.
x2 = 0.64

Simplifying
x2 = 0.64

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