Take 2 apples from 3 apples. what do you get?

To complete your spring schedule, you must add calculus and physics. at 9: 30, there are three calculus sections and two physics sections; while at 11: 30, there are two calculus sections and three physics sections. how many ways can you complete your schedule if your only open periods are 9: 30 and 11: 30?

Opposite angles in a parrellelogram are

How do i simply this radical expression?