(1+3+5+7+...+2007)--(2+4+6+8+...+2006)地等式怎么做
问题描述:
(1+3+5+7+...+2007)--(2+4+6+8+...+2006)地等式怎么做
答
(1+3+5+7+...+2007)-(2+4+6+8+...+2006)
=(1-2)+(3-4+(5-6)+……+(2005-2006)+2007
=-1+(-1)……+(-1)+2007(共2006/2个-1)
=-1003+2007
=-1004