国外恶搞视频大全 爆笑:(1+1/2)x(1-1/2)x(1+1/3)x(1-1/3)x..........x(1+1/9)x(1-1/9)=?

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/06 01:10:51
写出简算过程 满意可获30点积分

(1+1/2)x(1-1/2)x(1+1/3)x(1-1/3)x..........x(1+1/9)x(1-1/9)
=3/2*1/2*4/3*2/3*..........*10/9*8/9
=(3/2*4/3*5/4*..........*9/8*10/9)*(1/2*2/3*3/4*..........*7/8*8/9)
=10/2*1/9
=5/9

(1-1/4)(1-1/9)……(1-1/81)
=3*8*15*24*35*48*63*80/(4*9*16*25*36*49*64*81)
=约分=5/9

3/2*4/3*5/4*6/5*7/6*8/7*9/8*10/9
*
(1/2*2/3*3*4*4/5*5/6*6/7*7/8*8/9*9/10)
=(3*4*5*6*7*8*9*10/2*3*4*5*6*7*8*9)
/
(1*2*3*4*5*6*7*8*9/2*3*4*5*6*7*8*9*10)
=10÷2/0.1

=50