(-1).(-1)^2.(-1)^3.(-1)^4 ...(-1)^2010.(-1)^2011
Những câu hỏi liên quan
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)
Cho P = 1/2 + 1/3 +1/4 +...+1/2011 + 1/2012
Q = 1/2011 + 2/2010 + 3/2009 +...+ 2009/3 + 2010/2 + 2011/1
Cho A=1/2+1/3+1/4+...+1/2011+1/2012
B=2011/1+2010/2+2009/3+...+2/2010+1/2011
Tính A/B
Ta có \(B=\left(\frac{2010}{2}+1\right)+\left(\frac{2009}{3}+1\right)+...+\left(\frac{2}{2010}+1\right)+\left(\frac{1}{2011}+1\right)+1\)
\(B=\frac{2012}{2}+\frac{2012}{3}+...+\frac{2012}{2010}+\frac{2012}{2011}+\frac{2012}{2012}\)
\(B=2012.\left(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2010}+\frac{1}{2011}+\frac{1}{2012}\right)\)
B=2012.A
=>A/B=1/2012
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1. Cho A= 1/2 + 1/3 + 1/4 + ... + 1/2011 + 1/ 2012 và B= 2011/1 + 2010/2 + 2009/3 + ...+ 2/2010 + 1/2011
Tính: B/A { Giúp mik nhé ths }
TÍNH TỔNG : 1/1 : 2 + 1/2 : 3 + 1/3 : 4 + .........+ 1/2009:2010 + 1/2010 : 2011
Hình như đề bài phải là : Tính tổng : \(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{2009.2010}+\frac{1}{2010.2011}\)
Nếu thế giải như sau : \(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2009}-\frac{1}{2010}+\frac{1}{2010}-\frac{1}{2011}\)
\(=1-\frac{1}{2011}=\frac{2010}{2011}.\)Vậy tổng đó là 2010/2011.
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Ta có :\(\frac{1}{1}:2+\frac{1}{2}:3+...+\frac{1}{2010}:2011\)
= \(\frac{1}{1}\times\frac{1}{2}+\frac{1}{2}\times\frac{1}{3}+...+\frac{1}{2010}\times\frac{1}{2011}\)
= \(\frac{1}{1\times2}+\frac{1}{2\times3}+...+\frac{1}{2010\times2011}\)
= \(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{2010}-\frac{1}{2011}\)
= \(1-\frac{1}{2011}\)
= \(\frac{2010}{2011}\)
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Tính: C=(1/2+1/3+1/4+....+1/2012)/(2011/1+2010/2+.....+1/2011)
tinh tong :
1/1:2+1/2:3+1/3:4+...+1/2009:2010+1/2010:2011
Tìm x:
x . (1/2+1/3+1/4+. . .+1/2011+1/2012)
2012/1+2011/2+2010/3+2009/4+ . . . +2/2011+1/2012
=1
tính C=2010/1+2009/2 + 2008/3 +...+ 1/2010:1\2+1/3+1/4+......+1\2011
*2010/1+2009/2+...+1/2010
=(2009/2+1)+(2008/3+1)+...+(1/2010+1)+1
=2011/2+2011/3+..+2011/2010+2011/2011
=2011(1/2+1/3+1/4+...+1/2011)
=> C=2011/1=2011
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Tính: C=(1/2+1/3+1/4+....+1/2012)/(2011/1+2010/2+.....+1/2011)