2001-1+1999-2+1997-3+.1001-1000
计算1/1001+2/1001+3/1001+......+2001/1001=?
计算1001-1/2001-2/2001-3/2001-...-2001/2001
1/1001+2/1001+3/1001...2001/1001=?
(2001-1)+(2000-2)+(1999-3)+.+(1002-1000)=?
(2001-1)+(2000-2)+(1999-3)+.+(1002-1000)
(2002+2000+1998.+4+2)-(2001+1999+1997+.+3+1)简便运算,
1-2+3-4+5-6+…+1997-1998+1999-2000+2001简便运算
1+2-3-4+5+6-7-8+.+1997+1998-1999-2000+2001+2002
2001+2000-1999-1998+1997+1996-1995-1994+.+5+4-3-2+1
2002+2001-2000-1999+1998+1997-1996-1995.+6+5-4-3+2+1=?
2004+2003-2002-2001+2000+1999-1998-1997+...8+7-6-5+4+3-2-1
2004+2003-2002-2001+2000+1999-1998-1997+.+8+7-6-5+4+3-2-1