(4z+5)(4z-5)=

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

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

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

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

Multiply (5 + 4z) * (-5 + 4z)
(5(-5 + 4z) + 4z * (-5 + 4z)) = 0
((-5 * 5 + 4z * 5) + 4z * (-5 + 4z)) = 0
((-25 + 20z) + 4z * (-5 + 4z)) = 0
(-25 + 20z + (-5 * 4z + 4z * 4z)) = 0
(-25 + 20z + (-20z + 16z2)) = 0

Combine like terms: 20z + -20z = 0
(-25 + 0 + 16z2) = 0
(-25 + 16z2) = 0

Solving
-25 + 16z2 = 0

Solving for variable 'z'.

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

Add '25' to each side of the equation.
-25 + 25 + 16z2 = 0 + 25

Combine like terms: -25 + 25 = 0
0 + 16z2 = 0 + 25
16z2 = 0 + 25

Combine like terms: 0 + 25 = 25
16z2 = 25

Divide each side by '16'.
z2 = 1.5625

Simplifying
z2 = 1.5625

Take the square root of each side:
z = {-1.25, 1.25}