用另一种方法表示集合:C={1/1乘以2,1/2乘以3,1/3乘以4,1/4乘以5,……}
=3乘以2乘以1,=4乘以3乘以2乘以1,=5乘以4乘以3乘以2乘以1,那么100!除以99!
一乘以二乘以三分之一加2乘以3乘以4分之一+3乘以4乘以5分之1+……+48乘以49乘以50分之1.
1乘以2+2乘以3+3乘以4+4乘以5……+97乘以98+98乘以99+99乘以100等于多少
1乘以2乘以3乘以4乘以5乘以.100积有几个零
2乘以1+4乘以3+6乘以5直接加到50乘以49
1乘以2乘以3分之1+2乘以3乘以4分之1+……+98乘以99乘以100分之1
1乘以3分之2乘以4分之3乘以5分之4乘以.乘以20分之19等于多少?
观察1乘以2乘以3乘以4+1=25=5² 2乘以3乘以4乘以5+1=121=11²
1分之【1乘以2】+1/【2乘以3】+1/【3乘以4】+1/【4乘以5】+……+1/【2005乘以2006】等于多少.
1乘以2乘以3分之1+2乘以3乘以4分之1+3乘以4乘以5分之1+4乘以5乘以6分之1+········+48乘以49乘
1乘以2乘以3乘以4乘以一直乘到100等于多少?
1乘以2乘以3乘以4再乘以几等于100?