(x-4y)(x+9y)=

Solution for (x-4y)(x+9y)= equation:

Simplifying
(x + -4y)(x + 9y) = 0

Multiply (x + -4y) * (x + 9y)
(x(x + 9y) + -4y * (x + 9y)) = 0
((x * x + 9y * x) + -4y * (x + 9y)) = 0

Reorder the terms:
((9xy + x2) + -4y * (x + 9y)) = 0
((9xy + x2) + -4y * (x + 9y)) = 0
(9xy + x2 + (x * -4y + 9y * -4y)) = 0
(9xy + x2 + (-4xy + -36y2)) = 0

Reorder the terms:
(9xy + -4xy + x2 + -36y2) = 0

Combine like terms: 9xy + -4xy = 5xy
(5xy + x2 + -36y2) = 0

Solving
5xy + x2 + -36y2 = 0

Solving for variable 'x'.

Factor a trinomial.
(x + -4y)(x + 9y) = 0

Subproblem 1
Set the factor '(x + -4y)' equal to zero and attempt to solve:

Simplifying
x + -4y = 0

Solving
x + -4y = 0

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

Add '4y' to each side of the equation.
x + -4y + 4y = 0 + 4y

Combine like terms: -4y + 4y = 0
x + 0 = 0 + 4y
x = 0 + 4y
Remove the zero:
x = 4y

Simplifying
x = 4y
Subproblem 2
Set the factor '(x + 9y)' equal to zero and attempt to solve:

Simplifying
x + 9y = 0

Solving
x + 9y = 0

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

Add '-9y' to each side of the equation.
x + 9y + -9y = 0 + -9y

Combine like terms: 9y + -9y = 0
x + 0 = 0 + -9y
x = 0 + -9y
Remove the zero:
x = -9y

Simplifying
x = -9y
Solution
x = {4y, -9y}