计算:| 1/2003−1/2002 |+| 1/2004−1/2003 |−| 1/2004−1/2002 |

问题描述:

计算:

1
2003
1
2002
 |+| 
1
2004
1
2003
 |−| 
1
2004
1
2002
 |

原式=

1
2002
-
1
2003
+
1
2003
-
1
2004
+
1
2004
-
1
2002
=0.