(1/10*12 +1)(1/11*13 +1)(1/12*14 +1).(1/20*22 +1)
1/10*11+1/11*12+1/12*13+1/13*14+1/14*15等于?
|1/11-1/12|+|1/12-1/13|+|1/13-1/14+|1/14-1/15|
-1/10*11+1/11*12+1/12*13+1/13*14+···1/19*20的值
|1\12-1\11|+|3\13-1\12|+1\14-1\13|+|1\15-1\14|+||1\16-1\15|
1/10*11+1/11*12+1/12*13+1/13*14+1/14*15等于?我看不懂
(1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9+1/10+1/11+1/12+1/13+1/14+1/
有简便方法计算:|1/11-1/12|+|1/12-1/13|+|1/14-1/13|
1/11+1/33,1/12+1/29,1/13+1/25,1/14+1/21
1/11+1/29;1/12+1/25;1/14+1/19;1/13+1/21;
1\11+1\33,1\12+1\29,1\13+1\25,1\14+1\21
计算:1/9*10+1/10*11+1/11*12+1/12*13+1/13*14+1/14*15+1/15*16+1/
-1/10×11-1/11×12-1/12×13—……—1/19×20