1)A=2005^2005+1 trên 2005^2006+1 và B=2005^2004+1 trên 2005^2005     2)A=2006^2006+1 trên2007^2007+1 vàB=2006^2005+1 trên 2006^2006+1

Tinh A = \(\frac{\frac{2006}{1}+\frac{2006}{2}+\frac{2006}{3}+........\frac{2006}{2006}+\frac{2006}{2007}}{\frac{1}{2006}+\frac{2}{2005}+\frac{3}{2004}+.........+\frac{2005}{2}+\frac{2006}{1}}\)

Tìm tổng A, biết:

    A= -1+1+-2+2+-3+3+...+-2005+2005+-2006+2006

2/2005+1+2^2/2005^2+1+2^3/2005^3+1+....+2^n/2005^n+1....+2^2006/2005^2^2005+1

c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d

c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d

Cho : A = 1/1*2+1/3*4+1/5*6+.....+1/2003*2004+1/2005*2006

         B=1/1004*2006+1/1005*2005+1/1006*2004+....+1/2006*1004

Tinh: A/B

 2008+2007/2+2006/3+2005/4+2005/5+........................3/2006+2/2007+1/2008

1/2+1/3+1/4+1/5+....................+1/2009

 2008+2007/2+2006/3+2005/4+2005/5+........................3/2006+2/2007+1/2008

1/2+1/3+1/4+1/5+....................+1/2009

c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d  = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d