2005/1x2+2005
问题描述:
2005/1x2+2005
答
=2005x(1/1x2+1/2x3+.1/2004x2005)
=2005x(1/1-1/2+1/2-1/3+.1/2004-1/2005)
=2005x(1-1/2005)
=2005x2004/2005
=2004