用简便方法计算下列各题:(1)2003×2001/2002= (2) (5/6+4/5-2/3)×18=

来源:百度知道 编辑:UC知道 时间:2024/09/28 07:57:16

(1) 2003×2001/2002
=(2002+1)×2001/2002
=2002×2001/2002+1×2001/2002
=2001+2001/2002
=2001又2001/2002
(2)(5/6+4/5-2/3)×18
=5/6×18+4/5×18-2/3×18
=15+72/5-12
=3+14.4
=17.4

1 (2002+1)(2002-1)/2002
=(2002²- 1²)/2002
=2002-1/2002

(2/3+1/6+4/5-2/3)*18
=(1/6+4/5)*18
=(29/30)*18
=29*3/5
=87/5

2003×2001/2002=(2002+1)(2002-1)/2002=(2002^2-1)/2002=2002-1/2002
(5/6+4/5-2/3)×18=(1-1/6+1-1/5-1+1/3)×18=(1+1/6-1/5)×18=(1-1/30)×18=87/5