(1999+1997+1995+…+13+11)-(12+14+16+…+1996+1998)
问题描述:
(1999+1997+1995+…+13+11)-(12+14+16+…+1996+1998)
答
(1999+1997+1995+…+13+11)-(12+14+16+…+1996+1998),
=(1999-1998)+(1997-1996)+…+(13-12)+11,
=1×994+11,
=10055.