(4a+5b)(4a-5b)=

Solution for (4a+5b)(4a-5b)= equation:

Simplifying
(4a + 5b)(4a + -5b) = 0

Multiply (4a + 5b) * (4a + -5b)
(4a * (4a + -5b) + 5b * (4a + -5b)) = 0
((4a * 4a + -5b * 4a) + 5b * (4a + -5b)) = 0

Reorder the terms:
((-20ab + 16a2) + 5b * (4a + -5b)) = 0
((-20ab + 16a2) + 5b * (4a + -5b)) = 0
(-20ab + 16a2 + (4a * 5b + -5b * 5b)) = 0
(-20ab + 16a2 + (20ab + -25b2)) = 0

Reorder the terms:
(-20ab + 20ab + 16a2 + -25b2) = 0

Combine like terms: -20ab + 20ab = 0
(0 + 16a2 + -25b2) = 0
(16a2 + -25b2) = 0

Solving
16a2 + -25b2 = 0

Solving for variable 'a'.

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

Add '25b2' to each side of the equation.
16a2 + -25b2 + 25b2 = 0 + 25b2

Combine like terms: -25b2 + 25b2 = 0
16a2 + 0 = 0 + 25b2
16a2 = 0 + 25b2
Remove the zero:
16a2 = 25b2

Divide each side by '16'.
a2 = 1.5625b2

Simplifying
a2 = 1.5625b2

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