(3y+x)(3y-x)=

Solution for (3y+x)(3y-x)= equation:

Simplifying
(3y + x)(3y + -1x) = 0

Reorder the terms:
(x + 3y)(3y + -1x) = 0

Reorder the terms:
(x + 3y)(-1x + 3y) = 0

Multiply (x + 3y) * (-1x + 3y)
(x(-1x + 3y) + 3y * (-1x + 3y)) = 0
((-1x * x + 3y * x) + 3y * (-1x + 3y)) = 0

Reorder the terms:
((3xy + -1x2) + 3y * (-1x + 3y)) = 0
((3xy + -1x2) + 3y * (-1x + 3y)) = 0
(3xy + -1x2 + (-1x * 3y + 3y * 3y)) = 0
(3xy + -1x2 + (-3xy + 9y2)) = 0

Reorder the terms:
(3xy + -3xy + -1x2 + 9y2) = 0

Combine like terms: 3xy + -3xy = 0
(0 + -1x2 + 9y2) = 0
(-1x2 + 9y2) = 0

Solving
-1x2 + 9y2 = 0

Solving for variable 'x'.

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

Add '-9y2' to each side of the equation.
-1x2 + 9y2 + -9y2 = 0 + -9y2

Combine like terms: 9y2 + -9y2 = 0
-1x2 + 0 = 0 + -9y2
-1x2 = 0 + -9y2
Remove the zero:
-1x2 = -9y2

Divide each side by '-1'.
x2 = 9y2

Simplifying
x2 = 9y2

Take the square root of each side:
x = {-3y, 3y}