remember every term of one expression has to be multiplied with every term of the other expression, and the results are added up (while considering their individual signs, of course).
what is you math promblem.I think you are new to this app but if you want help with your homework you press the button that say ask a question and then u pick a subject and post it so other people could help you.But I can't help becuase you did not say what you need help on or your question