1*2*3/1+2*3*4/1+·····+11*12*13/1=
1*2*3/1+2*3*4/1+·····+11*12*13/1=
1+2++3+··········+10000=
把自然数从1开始,排列成下表:1 2 4 7 11 16······ 3 5 8 12 17······ 6 9 13
(1-2)×(2-3)×(3-4)×······×(19-20)=
俗语和名句的填空1······,自知之明.2······,行必果.3工欲善其事,······.4临渊羡鱼,······.
1\(2\3)\(3\4)······\(18\19)\(19\20)=
已知1+2+3+4+···+33=17*33计算1-3+2-6+3-9+4-12+·····
计算 1*2/1+2*3/1+3*4/1+············+2009*2010/1
1+2+3+4+5+6······38+39=?
1+2+3+4··· ···+78+79=?
计算1-2+3-4+5-6+······-98+99=
1+2+3+4+5······+100+101=几