Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1+2-3-4+5+6-7-8+9+..........+2002-2003-2004+2005
=1+(2-3-4+5)+(6-7-8+9)+............+(2002-2003-2004+2005)
=1+0+0+........+0
=1
\(\text{:1+2-3-4+5+6-7-8+9+10-...+2002-2003-2004+2005}\)
\(1+\left(2-3-4+5\right)+\left(6-7-8+9\right)+...+\left(2002-2003-2004+2005\right)\)
= \(1+0+0+....+0\)
= 1
=(1-2-3+4)+(5-6-7+8)+...+(2005-2006-2007+2008)+2009
=2009
\(B=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{5}\right)\cdot....\cdot\left(1-\frac{1}{2003}\right)\left(1-\frac{1}{2004}\right)\)
\(=\frac{2}{3}\cdot\frac{3}{4}\cdot\frac{4}{5}\cdot....\cdot\frac{2002}{2003}\cdot\frac{2003}{2004}\)
\(=\frac{2\cdot3\cdot4\cdot...\cdot2002\cdot2003}{3\cdot4\cdot5\cdot...\cdot2003\cdot2004}=\frac{1}{1002}\)
2000/2001 * 2002/2003 * 2001/2002 * 2003/2004*2006/2000
=((2000/2001).2002):2003.2001/2002).2003):2004.2006)/2000
=1.000998004
\(\dfrac{2000}{2001}\cdot\dfrac{2002}{2003}\cdot\dfrac{2001}{2002}\cdot\dfrac{2003}{2004}\cdot\dfrac{2006}{2000}=\dfrac{2006}{2004}=\dfrac{1003}{1002}\)
\(D=1-2-3+4+5-6-7+8+....+2001-2002-2003+2004\)
\(D=\left(1-2-3+4\right)+\left(5-6-7+8\right)+....+\left(2001-2002-2003+2004\right)\)
\(D=\left(-4+4\right)+\left(-8+8\right)+...+\left(-2004+2004\right)\)
\(D=0+0+...+0\)
\(\Rightarrow D=0\)