简便计算:1998*(1/11-1/2009)+11*(1/1998-2009)-2009*(1/11+1/1998)+3

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/26 05:18:24
简便计算:1998*(1/11-1/2009)+11*(1/1998-2009)-2009*(1/11+1/1998)+3简便计算:1998*(1/11-1/2009)+11*(1/1998-2009

简便计算:1998*(1/11-1/2009)+11*(1/1998-2009)-2009*(1/11+1/1998)+3
简便计算:1998*(1/11-1/2009)+11*(1/1998-2009)-2009*(1/11+1/1998)+3

简便计算:1998*(1/11-1/2009)+11*(1/1998-2009)-2009*(1/11+1/1998)+3
1998*(1/11-1/2009)+11*(1/1998-1/2009)-2009*(1/11+1/1998)+3
=1998/11-1998/2009+11/1998-11/2009-2009/11-2009/1998+3
=(1998-2009)/11-(1998+11)/2009+(11-2009)/1998+3
=-11/11-2009/2009-1998/1998+3
=-3+3
=0

直接拆开好像也简单

可以这样做:
1998*(1/11-1/2009)+11*(1/1998-1/2009)-2009*(1/11+1/1998)+3
=1998/11-1998/2009+11/1998-11/2009-2009/11-2009/1998+3
=(1998-2009)/11-(1998+11)/2009+(11-2009)/1998+3
=-11/11-2009/2009-1998/1998+3
=-3+3
=0
这可是我自己辛辛苦苦打出来的给好评。