3/2*5+3/5*8+3/8*11+...+3/2009*2012
问题描述:
3/2*5+3/5*8+3/8*11+...+3/2009*2012
答
3/2*5+3/5*8+3/8*11+...+3/2009*2012
=1/2-1/5+1/5-1/8+1/8-1/11+.+1/2009-1/2012
=1/2-1/2012
=(1006-1)/2012
=1005/2012