advanced factoring problem please help.?

Question

Hi,
i just came across a problem that seems very odd. I have no idea where to start this problem.
how do i factor:
x2y - x2 + 4y

if you can explain the steps that would be awesome. thank you.

Answer 1

if x2 is supposed to be x² , then you need to write it as x^2.

So if this really is supposed to be

x²y - x² + 4y

the only way I could factor anything is to take x² out of the first two terms to get:

x² (y-1) + 4y

or take y out of the first and third terms to get:

y (x² + 4) - x²