\(A=\frac{2008+2007+2002+2001+...+3+2+1}{2008-2007+2006-2005 +...+3-2+1}\)
Tìm x biết :
\(\frac{2-x}{2007}-1=\frac{1-x}{2008}-\frac{x}{2009}\)
Tính :
C=\(\frac{\frac{2006}{3}+\frac{2006}{3}+...+\frac{2006}{2007}}{\frac{2006}{1}+\frac{2005}{2}+...+\frac{1}{2006}}\)
tìm x biết \(\frac{1}{1x2}+\frac{1}{2x3}+....+\frac{1}{x\left(x+1 \right)}=\frac{2008}{2009}\)
\(\frac{1+2+2^2+...+2^{2008}}{1-2^{2009}}\)
CMR : tổng : P= 20062007 +20072008+20082009 chia hết cho 5
1 / giải phương trình sau:
\(\frac{1}{\left(x+2000\right).\left(x+2001\right)}+\frac{1}{\left(x+2001\right).\left(x+2002\right)}...\frac{1}{\left(x+2006\right)\left(x+2007\right)}=\frac{7}{8}\)
Tính
\(A=\left(1-\frac{1}{1+2}\right).\left(1-\frac{1}{1+2+3}\right)....\left(1-\frac{1}{1+2+3+...+2006}\right)\)
a/ So sánh 2^225 và 3^151
b/ So sánh không qua quy đồng
A=\(\frac{-7}{10^{2005}}+\frac{-15}{10^{2006}}\)và B=\(\frac{-15}{10^{2005}}+\frac{-7}{10^{2006}}\)
Giúp mình nha