X/X是分数
问题描述：
X/X是分数
1/1*2+1/2*3+1/3*4+…1/2002*2003
等于结果是?
答
(1 - 1/2) + (1/2 - 1/3) + (1/3 - 1/4) + (1/4 - 1/5) ...+ (1/2002 - 1/2003)
= 1 - 1/2003
= 2002/2003