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:
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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+
2
/5
单选题
难度:
2.要组织一次排球邀请赛,参赛的每个队之间都要比赛一场,根据场地和时间等条件,赛程计划安排7天,每天安排4场比赛. 设比赛组织者应邀请x个队参赛,则x满足的关系式为( )
A
B
C
x(x+1)=28
D
x(x-1)=28
提示1:
IOWFs+ezu+W8j+S4uu+8mueQg+mYn+aAu+aVsMOX5q+P5pSv55CD6Zif6ZyA6LWb55qE5Zy65pWww7cyPTTDlzfvvIzmiornm7jlhbPmlbDlgLzku6PlhaXljbPlj68u
正确答案:
Qg==
6Kej77ya5q+P5pSv55CD6Zif6YO96ZyA6KaB5LiO5YW25LuW55CD6Zif6LWb77yIeC0x77yJ5Zy677yM5L2GMumYn+S5i+mXtOWPquaciTHlnLrmr5TotZvvvIw8YnI+5omA5Lul5Y+v5YiX5pa556iL5Li677yaPGltZyB3aWR0aD0xMDggaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvNDAvMEIvckJBQ0ZGUFY3Z1hBSXBfNUFBQUNVSG1ZYlR3NDE2LnBuZyI+
3
/5
单选题
难度:
3.某班学生打算在毕业时,每个同学都将自己的相片向全班其他同学各留一张作纪念,全班共送了4160张相片. 如果全班有x名学生,根据题意,列出方程是( )
A
x(x-1)=4160
B
x(x+1)=4160
C
2x(x+1)=4160
D
=4160
提示1:
IOagueaNrumimOaEj+W+l++8muWFqOePreaciXjlkI3lrabnlJ/vvIzmr4/lkI3lrabnlJ/opoHotaDpgIHvvIh4LTHvvInlvKDnm7jniYc=
提示2:
IOagueaNrui1oOmAgeebuOeJh+aAu+W8oOaVsOS4jeWPmOWPr+WIl+WHuuaWueeoi++8mnjvvIh4LTHvvIk9NDE2MC4=
正确答案:
QQ==
6Kej77ya6K6+5YWo54+t5pyJeOWQjeWtpueUn++8jOWImeavj+WQjeWtpueUn+imgei1oOmAge+8iHgtMe+8ieW8oOebuOeJh++8jOagueaNrumimOaEj+W+l++8mjxicj5477yIeC0x77yJPTQxNjAuIDxicj7mlYXpgIlBLiA=
4
/5
单选题
难度:
4.已知一人得了流感,经过两轮传染后,患病总人数为121人,设平均每人传染了x个人,则下列方程正确的是( )
A
1+x+x
2
=121
B
(1+x)
2
=121
C
1+(1+x)+(1+x)
2
=121
D
1+x
2
=121
提示1:
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正确答案:
Qg==
6Kej77ya6K6+5bmz5Z2H5q+P5Lq65Lyg5p+T5LqGeOS4quS6uu+8jOWImTxicj7vvIgxK3jvvIk8c3VwPjI8L3N1cD49MTIxLiA8YnI+5pWF6YCJQi4g
5
/5
单选题
难度:
5.有x支球队进行足球单循环比赛(既每两个队之间都要进行一场比赛),共比赛了21场,列出方程是( )
A
x(x-1)=21
B
C
x(x+1)=21
D
提示1:
IOi1m+WItuS4uuWNleW+queOr+W9ouW8j++8iOavj+S4pOmYn+S5i+mXtOmDvei1m+S4gOWcuu+8ie+8jHjkuKrnkIPpmJ/mr5TotZvmgLvlnLrmlbA8aW1nIHdpZHRoPTQ2IGhlaWdodD00MiBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzQwLzBFL3JCQUNGRlBWN2xxaUpFVDRBQUFCdkMtbnhKQTI4OC5wbmciPg==
正确答案:
Qg==
6Kej77ya6K6+5pyJeOS4qumYn++8jOavj+S4qumYn+mDveimgei1m++8iHgtMe+8ieWcuu+8jOS9huS4pOmYn+S5i+mXtOWPquacieS4gOWcuuavlOi1m++8jDxpbWcgd2lkdGg9ODAgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvN0QvNUMvckJBQ0UxUFY3bHFDTnpmMkFBQUNNWGx5WS1NOTkwLnBuZyI+PGJyPuaVhemAiUIuIA==