Question

Factor
(x-3y)2-(y-x)2

Answer 1

To factor (x-3y)2-(y-x)2, you would expand, or multiply out the terms. Some of them may cancel, others may add up.
(x-3y)2-(y-x)2
=2x -6y - 2y + 2x
Collect the terms and find the common factors of the coefficients
=4x -8y
So the common factor is 4
= 4(x-2y)