(2+4+6+8+...2n)-{1+3+5+7+...+(2n-1)}
问题描述:
(2+4+6+8+...2n)-{1+3+5+7+...+(2n-1)}
答
(2+4+6+8+...2n)-{1+3+5+7+...+(2n-1)} =(2-1)+(4-3)+……+{2n-(2n-1)}=1*n=n
(2+4+6+8+...2n)-{1+3+5+7+...+(2n-1)}
(2+4+6+8+...2n)-{1+3+5+7+...+(2n-1)} =(2-1)+(4-3)+……+{2n-(2n-1)}=1*n=n