1+2+3+***+49+50 =
问题描述:
1+2+3+***+49+50 =
答
1+2+3+……+49+50
=(1+50)×50÷2
=51×25
=1275
1+2+3+***+49+50 =
1+2+3+……+49+50
=(1+50)×50÷2
=51×25
=1275