(5s+4)(5s-4)=

Solution for (5s+4)(5s-4)= equation:

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

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

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

Multiply (4 + 5s) * (-4 + 5s)
(4(-4 + 5s) + 5s * (-4 + 5s)) = 0
((-4 * 4 + 5s * 4) + 5s * (-4 + 5s)) = 0
((-16 + 20s) + 5s * (-4 + 5s)) = 0
(-16 + 20s + (-4 * 5s + 5s * 5s)) = 0
(-16 + 20s + (-20s + 25s2)) = 0

Combine like terms: 20s + -20s = 0
(-16 + 0 + 25s2) = 0
(-16 + 25s2) = 0

Solving
-16 + 25s2 = 0

Solving for variable 's'.

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

Add '16' to each side of the equation.
-16 + 16 + 25s2 = 0 + 16

Combine like terms: -16 + 16 = 0
0 + 25s2 = 0 + 16
25s2 = 0 + 16

Combine like terms: 0 + 16 = 16
25s2 = 16

Divide each side by '25'.
s2 = 0.64

Simplifying
s2 = 0.64

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