(y+9x)(y-9x)=

Solution for (y+9x)(y-9x)= equation:

Simplifying
(y + 9x)(y + -9x) = 0

Reorder the terms:
(9x + y)(y + -9x) = 0

Reorder the terms:
(9x + y)(-9x + y) = 0

Multiply (9x + y) * (-9x + y)
(9x * (-9x + y) + y(-9x + y)) = 0
((-9x * 9x + y * 9x) + y(-9x + y)) = 0

Reorder the terms:
((9xy + -81x2) + y(-9x + y)) = 0
((9xy + -81x2) + y(-9x + y)) = 0
(9xy + -81x2 + (-9x * y + y * y)) = 0
(9xy + -81x2 + (-9xy + y2)) = 0

Reorder the terms:
(9xy + -9xy + -81x2 + y2) = 0

Combine like terms: 9xy + -9xy = 0
(0 + -81x2 + y2) = 0
(-81x2 + y2) = 0

Solving
-81x2 + y2 = 0

Solving for variable 'x'.

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

Add '-1y2' to each side of the equation.
-81x2 + y2 + -1y2 = 0 + -1y2

Combine like terms: y2 + -1y2 = 0
-81x2 + 0 = 0 + -1y2
-81x2 = 0 + -1y2
Remove the zero:
-81x2 = -1y2

Divide each side by '-81'.
x2 = 0.01234567901y2

Simplifying
x2 = 0.01234567901y2

Take the square root of each side:
x = {-0.111111111y, 0.111111111y}