Is homework an excuse to not go to an event?

I have so much homework I have to do and its too much. I have three assignments due Friday. One if my friends asked if I still want to go to the art show and it ends at 8:30. Plus I have school the next day. My other assigment I read I haven't written yet becasue I had other assignments. They told me if I can't make it because of it its okay and they want me to succeed.