79*69/80怎样简便算
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/18 20:24:17
79*69/80怎样简便算79*69/80怎样简便算79*69/80怎样简便算79*69/80=(80-1)*69/80=80*69/80-1*69/80=69-69/80=68又11/8079*69
79*69/80怎样简便算
79*69/80怎样简便算
79*69/80怎样简便算
79*69/80
=(80-1)*69/80
=80*69/80-1*69/80
=69-69/80
=68又11/80
79*69/80
=（80-1）×69/80
=80×69/80-1×69/80
=69-69/80
=68又11/80
呵呵，把79看成（80-1）就好办了~再把括号拆开，这就是这道题的简便…………那9/20*101*9/20？原题 =0.45×0.45×101 =0.45×（100+1）×0.45 =（0.45×100+0.45×1）×0.45 ...
全部展开
79*69/80
=（80-1）×69/80
=80×69/80-1×69/80
=69-69/80
=68又11/80
呵呵，把79看成（80-1）就好办了~再把括号拆开，这就是这道题的简便…………
收起
=(80-1)*69/80
=80*69/80-1*69/80=69-69/80=68又11/80