(3x-9y)(-2x-7y)=

Solution for (3x-9y)(-2x-7y)= equation:

Simplifying
(3x + -9y)(-2x + -7y) = 0

Multiply (3x + -9y) * (-2x + -7y)
(3x * (-2x + -7y) + -9y * (-2x + -7y)) = 0
((-2x * 3x + -7y * 3x) + -9y * (-2x + -7y)) = 0

Reorder the terms:
((-21xy + -6x2) + -9y * (-2x + -7y)) = 0
((-21xy + -6x2) + -9y * (-2x + -7y)) = 0
(-21xy + -6x2 + (-2x * -9y + -7y * -9y)) = 0
(-21xy + -6x2 + (18xy + 63y2)) = 0

Reorder the terms:
(-21xy + 18xy + -6x2 + 63y2) = 0

Combine like terms: -21xy + 18xy = -3xy
(-3xy + -6x2 + 63y2) = 0

Solving
-3xy + -6x2 + 63y2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-1xy + -2x2 + 21y2) = 0

Factor a trinomial.
3((-2x + -7y)(x + -3y)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-2x + -7y)' equal to zero and attempt to solve:

Simplifying
-2x + -7y = 0

Solving
-2x + -7y = 0

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

Add '7y' to each side of the equation.
-2x + -7y + 7y = 0 + 7y

Combine like terms: -7y + 7y = 0
-2x + 0 = 0 + 7y
-2x = 0 + 7y
Remove the zero:
-2x = 7y

Divide each side by '-2'.
x = -3.5y

Simplifying
x = -3.5y
Subproblem 2
Set the factor '(x + -3y)' equal to zero and attempt to solve:

Simplifying
x + -3y = 0

Solving
x + -3y = 0

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

Add '3y' to each side of the equation.
x + -3y + 3y = 0 + 3y

Combine like terms: -3y + 3y = 0
x + 0 = 0 + 3y
x = 0 + 3y
Remove the zero:
x = 3y

Simplifying
x = 3y
Solution
x = {-3.5y, 3y}