Math problems When participating in a chess game, participants need to shake hands with each other. Someone shook hands 36 times and asked how many people attended.
Suppose there are x people. If everyone takes the initiative to shake hands with others, each person needs X- 1 time, and the total * * needs X*(X- 1) times, and the topic only needs two people to shake hands regardless of priority (that is, the single cycle problem), then the total * * needs X*(X-65438).