(1/11+1/20+1/31+1/40)*(1/21+1/30+1/41+1/50)-(1/11+1/21+1/31+
来源:学生作业帮 编辑:百度作业网作业帮 分类:数学作业 时间:2024/06/17 23:21:35
(1/11+1/20+1/31+1/40)*(1/21+1/30+1/41+1/50)-(1/11+1/21+1/31+1/41+1/51)*(1/21+1/31+1/41)=?
题目错了吧?
题目是不是这样的:
(1/11+1/21+1/31+1/41)*(1/21+1/31+1/41+1/51)-(1/11+1/21+1/31+1/41+1/51)*(1/21+1/31+1/41)
令a=1/21+1/31+1/41
∴原式=(1/11+a)*(a+1/51)-(1/11+a+1/51)*a
=a/11+a²+1/11*51+a/51-a/11-a²-a/51
=1/561
题目是不是这样的:
(1/11+1/21+1/31+1/41)*(1/21+1/31+1/41+1/51)-(1/11+1/21+1/31+1/41+1/51)*(1/21+1/31+1/41)
令a=1/21+1/31+1/41
∴原式=(1/11+a)*(a+1/51)-(1/11+a+1/51)*a
=a/11+a²+1/11*51+a/51-a/11-a²-a/51
=1/561
(1/11+1/20+1/31+1/40)*(1/21+1/30+1/41+1/50)-(1/11+1/21+1/31+
(1/11+1/21+1/31+1/41)*(1/21+1/31+1/41+1/51)-(1/11+1/21+1/31+
1 {1/11+1/21+1/31+1/41}*{1/21+1/31+1/41+1/51}-{1/11+1/21+1/3
(1/11+1/21+1/31++1/41)*(1/21+1/31++1/41+1/51)-(1/11+1/21+1/3
骆驼祥子1-10页 11-20 21-30 31-40 41-50……主要内容,好词好句,感想
求骆驼祥子1-10页 11-20 21-30 31-40 41-50的主要内容
1+11+21+31+41+51+61+71+81+9
1 /6×11+1/11×16+1/16×21+1/21×26+1/26×31+1/31×36 =
1+11+21+31+.+101+111
(21分之1+31分之1+41分之1)*(31分之1+41分之1+51分之1)-(21分之1+31分之1+41分之1+5
在(1/17+1/19)*20,(1/24+1/29)*30,(1/31+1/37)*40,(1/41+1/47)*50
计算1/(6*11)+1/(11*16)+1/(16*21)+1/(21*26)+1/(26*31)+1/(31*36)