1+2-3+4-5+…-99+100=_.
问题描述:
1+2-3+4-5+…-99+100=______.
答
1+2-3+4-5+…-99+100,
=1-[(3-2)+(5-4)+…+(99-98)]+100,
=1-[1×49]+100,
=1-49+100,
=52;
故答案为:52.