4个回答
1+(-2)+3+(-4)+5+(-6)+…+99+(-100).
=（-1）*100/2
=（-1）*50
=-50
1-2+3-4+5-6+...+99-100
=(1-2)+(3-4)+(5-6)+...+(99-100)
=-1-1-1-1……-1
=50*（-1）=-50
1+（-2）+3+(-4)+5+(-6)+……+99+（-100)
=(1-2)+(3-4)+(5-6)+...+(99-100)
=-1-1-1-1...-1
=-1*50=-50
1+(-2)+3+(-4)+5+(-6)+…+99+(-100).
=（1-2）+（3-4）+……+（99-100）
= -1×50
= -50