Question

xy9-yx9 factories it

Answer 1

(xy9-yx9) = xy(9-9)=xy*0=0

Answer 2

So you start with $xy9 -yx9$

First you can factor out an x which will leave you with $x(y9-y9)$

Additionally you can factor out both the y and the 9 which would leave you with $9xy(1-1)$ (I would assume this is what your answer would be but I am not sure of how your other answers are formatted.)

If not it would simplify even more to $9xy(0)$

Which would turn into $0$