六年级数学简算题(1/2+1/3+…+1/2010)*(1+1/2+1/3+…+1/2009)-(1+1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)

来源:学生作业帮助网 编辑:作业帮 时间:2024/10/06 16:37:55
六年级数学简算题(1/2+1/3+…+1/2010)*(1+1/2+1/3+…+1/2009)-(1+1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)
xSN@.f(+LK10D7](P(ҰO+~X6v=sܔE!^ދ4 -W̆l6}i) ` yC80;_EhIa/r=n \,ʯkڕug@1,ՙaZ(!8 ۏmF ð1X-i)AiP.'!BΗI+L<ܒ#V $9DLF [rjCd(Mۖ}H8q~Lq2$ͣp]5k5]uH ׵{cBf1e&/D 3f~Ȗu5mܔEǦI'0HC왺 Kx::%z wc!~+z3߷3];DLHt8 _S'z

六年级数学简算题(1/2+1/3+…+1/2010)*(1+1/2+1/3+…+1/2009)-(1+1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)
六年级数学简算题(1/2+1/3+…+1/2010)*(1+1/2+1/3+…+1/2009)-(1+1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)

六年级数学简算题(1/2+1/3+…+1/2010)*(1+1/2+1/3+…+1/2009)-(1+1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)
(1/2+1/3+…+1/2010)*(1+1/2+1/3+…+1/2009)-(1+1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)
=(1/2+1/3+…+1/2010)*1+(1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)
-1*(1/2+1/3+…+1/2009) -(1/2+1/3+…+1/2010)*(1/2+1/3+…+1/2009)
==(1/2+1/3+…+1/2010)*1-1*(1/2+1/3+…+1/2009) =1/2010

设(1/2+1/3+…+1/2009)=x,则
=(x+1/2010)*(1+x)-(1+x+1/2010)x
=(x^2+x+x/2010+1/2010)-(x^2+x-x/2010)
=1/2010

1/2010

首先假设:1/2+1/3+…+1/2009=A ,于是原式就变成:
(A+1/2010)*(1+A)-(1+A+1/2010)*(A)
然后在第一个括号里填上(+1和-1),于是就变成:
(1+A+1/2010-1)*(1+A)-(1+A+1/2010)*(A)
接下来将两个乘积按分配律展开:
(1+A+1...

全部展开

首先假设:1/2+1/3+…+1/2009=A ,于是原式就变成:
(A+1/2010)*(1+A)-(1+A+1/2010)*(A)
然后在第一个括号里填上(+1和-1),于是就变成:
(1+A+1/2010-1)*(1+A)-(1+A+1/2010)*(A)
接下来将两个乘积按分配律展开:
(1+A+1/2010-1)*(1+A)-(1+A+1/2010)*(A)
=(1+A+1/2010)*(1+A)-1×(1+A)-(1+A+1/2010) *(A)
=(1+A+1/2010)【(1+A)-(A)】-1×(A)
=(1+A+1/2010)-(1+A)
= 1+A+1/2010-1-A
= 1/2010

收起