(9a+4b)(9a-4b)=

Solution for (9a+4b)(9a-4b)= equation:

Simplifying
(9a + 4b)(9a + -4b) = 0

Multiply (9a + 4b) * (9a + -4b)
(9a * (9a + -4b) + 4b * (9a + -4b)) = 0
((9a * 9a + -4b * 9a) + 4b * (9a + -4b)) = 0

Reorder the terms:
((-36ab + 81a2) + 4b * (9a + -4b)) = 0
((-36ab + 81a2) + 4b * (9a + -4b)) = 0
(-36ab + 81a2 + (9a * 4b + -4b * 4b)) = 0
(-36ab + 81a2 + (36ab + -16b2)) = 0

Reorder the terms:
(-36ab + 36ab + 81a2 + -16b2) = 0

Combine like terms: -36ab + 36ab = 0
(0 + 81a2 + -16b2) = 0
(81a2 + -16b2) = 0

Solving
81a2 + -16b2 = 0

Solving for variable 'a'.

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

Add '16b2' to each side of the equation.
81a2 + -16b2 + 16b2 = 0 + 16b2

Combine like terms: -16b2 + 16b2 = 0
81a2 + 0 = 0 + 16b2
81a2 = 0 + 16b2
Remove the zero:
81a2 = 16b2

Divide each side by '81'.
a2 = 0.1975308642b2

Simplifying
a2 = 0.1975308642b2

Take the square root of each side:
a = {-0.444444444b, 0.444444444b}