One third of the attendees at a concert left the show before the encore. Twenty more people left during the encore. After the encore, half as many people as had left before the encore left. If 76 people remained in the theater after the concert was over to try to get autographs from the band, how many people, in total, attended the concert? Please write it out step by step. Thank You.

If x+y=r and x-y=s, in terms of x and y, what is r^2-s^2? Please show step by step. Thanks.

If x2 + y2 = 14 and xy = 3, which of the following is equal to (x + y)^2?

Could you go step by step?