问题
填空题
1-2+3-4+5-6+7-8+…+4999-5000=______.
答案
1-2+3-4+5-6+7-8+…+4999-5000
=(1-2)+(3-4)+(5-6)+(7-8)+…+
=(-1)+(-1)+(-1)+(-1)+…+(-1)
=-2500.
故答案为:-2500
1-2+3-4+5-6+7-8+…+4999-5000=______.
1-2+3-4+5-6+7-8+…+4999-5000
=(1-2)+(3-4)+(5-6)+(7-8)+…+
=(-1)+(-1)+(-1)+(-1)+…+(-1)
=-2500.
故答案为:-2500