1-1/2+1/3-1/4+1/5-1/6+...+1/2011-1/2012    /      1006-1006/1007-1007/1008-1008/1009-...-2010/2011-2011/2012

tính nhanh giá trị biểu thức

1-1/2+1/3-1/4+1/5-1/6+....+1/2011-1/2012

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1006-1006/1007-1007/1008-1008/1009-...-2010/2011-2011/2012

---------- là phần nha

trình bày cách giải

CMR: 1/1005+1/1006+1/1007+...+1/2009+ 1-1/2+1/3-1/4+...+1/2008+1/2009

5-x/2010+4-x/2011+3-x/2012=6-x/2009+1-x/1007

ai đó giúp mk với mk xin chân thành cảm ơn! a=(2010+2010/2+2009/3+2008/4+...+1/2011/ 1/2+1/3+...+1/2011) / (1/2+1/3+1/4+1/5+...+1/2009+1/2010+1/2011)

a) 2010/1+2009/2+2008/3+ ... +1/2010+2010 : 1+1/2+1/3+ ... +1/2010=

b) 1/2011+1/2010+1/2009+ ... +1/3+1/2 : 2010/1+2009/2+2008/3+ ... +1/2010=

Cho A = 1/2001+2/2009+3/2008+........2009/+ 2010/1, B = 1+1/2+1/3+1/4+1/5+1/6+.......1/2010+1/2011. Tính A/B

Tinh\(\frac{\frac{2010}{1}+\frac{2009}{2}+\frac{2008}{3}+...+\frac{2}{2009}+\frac{1}{2010}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+...+\frac{1}{2010}+\frac{1}{2011}}\)

So sánh a và b

A=1/2010+1/2011+1/2012

B=1/2009+1/1007