50눀-49눀+48눀-47눀+46눀-45눀+……+2눀-1눀

2024-12-27 01:17:25
推荐回答(1个)
回答1:


=(50-49)(50+49)+(48-47)(48+47)+……+(2-1)(2+1)
=50+49+48+………+2+1
=(50+1)×50÷2
=1275