来自陈阳军的问题
数学简便计算题快(1/5+1/7+1/9)+(1/7+1/9+1/11)+(1/7+1/9)*(1/5+1/7+1/9+1/11)简便计算
数学简便计算题快
(1/5+1/7+1/9)+(1/7+1/9+1/11)+(1/7+1/9)*(1/5+1/7+1/9+1/11)
简便计算
3回答
2020-04-11 09:23
数学简便计算题快(1/5+1/7+1/9)+(1/7+1/9+1/11)+(1/7+1/9)*(1/5+1/7+1/9+1/11)简便计算
数学简便计算题快
(1/5+1/7+1/9)+(1/7+1/9+1/11)+(1/7+1/9)*(1/5+1/7+1/9+1/11)
简便计算
(1/5+1/7+1/9)*(1/7+1/9+1/11)-(1/7+1/9)*(1/5+1/7+1/9+1/11)=(1/5+1/7+1/9)*(1/5+1/7+1/9+1/11)-(1/7+1/9)*(1/5+1/7+1/9+1/11)-1/5*(1/5+1/7+1/9)=1/5*(1/5+1/7+1/9+1/11)-1/5*(1/5+1/7+1/9)=1/5*1/11=1/55.
不知道正确吗
。。。。。难道你没发现我把加号抄成减号了吗