An expression is shown below:
2x3y + 18xy - 10x2y - 90y

part a: rewrite the expression so that the gcf is factored completely. part b: rewrite the expression completely factored. show the steps of your work.

part c: if the two middle terms were switched so that the expression became 2x3y - 10x2y + 18xy - 90y, would the factored expression no longer be equivalent to your answer in part b? explain your reasoning.