1+3+5+7+...+107+109-2-4-6-8-...-106-108

问题描述:

1+3+5+7+...+107+109-2-4-6-8-...-106-108

(1+3+5+7+……+97+109)-(2+4+6+8+……+98+108)
=(1+109)*(55/2)-(2+108)*(55/2)
=110*27.5-110*27.5
=(100-100)*27.5
=0