挑战习题
1/5单选题
难度:

1.在某次聚会上,每两人都握了一次手,所有人共握手10次,设有x人参加这次聚会,则列出方程正确的是(  )
A x(x-1)=10
B
C x(x+1)=10
D
提示1:
IOWmguaenOaciXjkurrlj4LliqDkuobogZrkvJrvvIzliJnmr4/kuKrkurrpnIDopoHmj6HmiYvvvIh4LTHvvInmrKHvvIx45Lq65YWx6ZyA5o+h5omLeO+8iHgtMe+8ieasoe+8mw==
提示2:
IOiAjOavj+S4pOS4quS6uumDveaPoeS6huS4gOasoeaJi++8jOWboOatpOimgeWwhumHjeWkjeiuoeeul+eahOmDqOWIhumZpOWOuw==
提示3:
IOW3suefpeKAnOaJgOacieS6uuWFseaPoeaJizEw5qyh4oCd77yM5o2u5q2k5Y+v5YiX5Ye65YWz5LqOeOeahOaWueeoiy4=
正确答案:Qg==
6Kej77ya6K6+eOS6uuWPguWKoOi/measoeiBmuS8mu+8jOWImeavj+S4quS6uumcgOaPoeaJi++8mngtMe+8iOasoe+8ie+8mzxicj7kvp3popjmhI/vvIzlj6/liJfmlrnnqIvkuLrvvJo8aW1nIHdpZHRoPTgwIGhlaWdodD00MiBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzQwLzBCL3JCQUNGRlBWN2Y2anpSZjhBQUFDSDJ6OXBkSTc0My5wbmciPjxicj7mlYXpgIlCLiA8YnI+