Tính:
\(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}}{\frac{2011}{1}+\frac{2010}{2}+..+\frac{1}{2011}}\)
\(A=\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\cdot\cdot\cdot+\frac{1}{2011}+\frac{1}{2012}\)
\(B=\frac{2011}{1}+\frac{2010}{2}+\frac{2009}{3}+\cdot\cdot\cdot\frac{2}{2010}+\frac{1}{2011}\)
Tính \(\frac{B}{A}\)
1. Tinh a \(\left(6^9.2^{10}+12^{10}\right)+\left(2^{19}.27^3+15.4^9.9^4\right)\)
2. So sanh A va B.
a) \(A=\frac{-2012}{4025};B=\frac{-1999}{3997}\)
b) \(A=3^{21};B=2^{31}\)
c) \(A=\frac{2011}{1.2}+\frac{2011}{3.4}+\frac{2011}{5.6}+....+\frac{2011}{1999.2000};\)\(B=\frac{2012}{1001}+\frac{2012}{1002}+\frac{2012}{1003}+....+\frac{2012}{2000}\)
Cho A= \(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}}{2012+\frac{2012}{2}+\frac{2011}{3}+...+\frac{1}{2013}}\)
tính A
Cho \(A=\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2011}+\frac{1}{2012}\)
\(B=\frac{2011}{1}+\frac{2010}{2}+\frac{2009}{3}+....+\frac{2}{2010}+\frac{1}{2011}\)
Tính \(\frac{A}{B}\)
Tìm số hữu tỉ x biết:
a) \(\frac{x+4}{2009}+\frac{x+3}{2010}=\frac{x+2}{2011}+\frac{x+1}{2012}\)
b) \(\frac{x-2011}{2010}+\frac{x-2011}{2011}+\frac{x-2011}{2012}=\frac{x-2011}{2013}+\frac{x-2011}{2014}\)
Rút gọn \(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}}{2012+\frac{2012}{2}+\frac{2011}{3}+...+\frac{1}{2013}}\)ta đc A= ?
Rút gọn A=\(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}}{2012+\frac{2012}{2}+\frac{2011}{3}+...+\frac{1}{2013}}\)Ta được A=
Rút gọn A=\(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}}{2012+\frac{2012}{2}+\frac{2011}{3}+...+\frac{1}{2013}}\)Ta được A=...