20-19+18-17+16-15+14-13+12-11最简单的计算方法

14,15,16,17,18,19,20 20-19+18-17+16-15+14-.-2+1=? 11 12 13 14 15 16 17 18 19 20 20×20-19×19+18×18-17×17+16×16-15×15+14×14...+2×2-1×1 怎么算? 14/15/16/17/18/19题,.. 14,15,16,17,18,19 14 15 16 17 18 19 物理14-15-16-17-18-19 17,18,15,14,19,20,13, 10,20,14,13,18,15,16,16,16,19,(),17 15 16 17 18 19 20 15 16 17 18 19 20 15 16 17 18 19 20 15,16,17,18,19,20题 12,14,15,16,18,19,20 1/(12*13)+1/(13*14)+1/(14*15)+1/(15*16)+1/(16*17)+1/(17*18)+1/(18*19)+1/(19*20)=? 11,12,13,14,15,16,17,18,19,20的英文怎么写? 11 12 13 14 15 16 17 18 19 20 的英语怎么说