11-12+13-14+15-16+17-18+19-20+21的简便计算

2025-06-26 20:22:31
推荐回答(1个)
回答1:

11+21=32 -(12+20)= - 32
13+19=32 -(14+18)= - 32
15+17=32
32 -16=16