(3a-b)*(3a+b)=

Solution for (3a-b)*(3a+b)= equation:

Simplifying
(3a + -1b)(3a + b) = 0

Multiply (3a + -1b) * (3a + b)
(3a * (3a + b) + -1b * (3a + b)) = 0
((3a * 3a + b * 3a) + -1b * (3a + b)) = 0

Reorder the terms:
((3ab + 9a2) + -1b * (3a + b)) = 0
((3ab + 9a2) + -1b * (3a + b)) = 0
(3ab + 9a2 + (3a * -1b + b * -1b)) = 0
(3ab + 9a2 + (-3ab + -1b2)) = 0

Reorder the terms:
(3ab + -3ab + 9a2 + -1b2) = 0

Combine like terms: 3ab + -3ab = 0
(0 + 9a2 + -1b2) = 0
(9a2 + -1b2) = 0

Solving
9a2 + -1b2 = 0

Solving for variable 'a'.

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

Add 'b2' to each side of the equation.
9a2 + -1b2 + b2 = 0 + b2

Combine like terms: -1b2 + b2 = 0
9a2 + 0 = 0 + b2
9a2 = 0 + b2
Remove the zero:
9a2 = b2

Divide each side by '9'.
a2 = 0.1111111111b2

Simplifying
a2 = 0.1111111111b2

Take the square root of each side:
a = {-0.333333333b, 0.333333333b}