13+2-5=?(2)(4乘以9+26)除以9=?(3)(19+20)除以4-0=?…

1乘以2乘以3+2乘以3乘以4+3乘以4乘以5+...+7乘以8乘以9 =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! 0除以3乘以4乘以5乘以6乘以7乘以8乘以9乘以10除以3除以2等于 1乘以2乘以3乘以4乘以5乘以.100积有几个零 1乘以2乘以3乘以4乘以5乘以...乘以2010的末尾有（ ）个连续的零. 900乘以2/9乘以4/5等于多少? 1乘以2乘以3分之1加上2乘以3乘以4分之1加上3乘以4乘以5分之1加上.11乘以12乘以13分之1等于多少....................................... 1除以(1乘以2乘以3)加上1除以(2乘以4乘以3)加上1除以(3乘以4乘以5)加上.1除以(8乘以9乘以10) 分数简算 3/4乘以16= 12除以3/5= 0.3乘以5/6= 1除以7/8=5/7乘以2/3除以5/7 1/2乘以1/3除以1/2乘以1/3 0乘以7/12+1/8 48乘以（7/12+1/3）除以2/3 23-8/9乘以3/4除以1/27 5除以[（2/3+1/5）乘以1/13] 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+2乘以3+4乘以5+6乘以7+8乘以9=1005 在上面各式当中添上适当的括号使等式成立 7乘以(未知数+2)=5乘以(未知数+9)12乘以（60-未知数）=7乘以（20-未知数） 计算:1/1乘以3+1/2乘以4+1/3乘以5+...+1/9乘以11 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=11²3乘以4乘以5乘以6+1=361=19²（1）计算5乘以6乘以7乘以8+1的结果是多少?（2）由此你能推出一般的结论吗? 写得数:3/5乘以1/4,11/25乘以5/33,六乘以1/3乘以2/5,77/100乘以零乘以写得数:3/5乘以1/4,11/25乘以5/33,六乘以1/3乘以2/5,77/100乘以零乘以8/9,答案请写在纸上, 1/1乘以2乘以3+1/2乘以3乘以4+1/3乘以4乘以5…+1/20乘以21乘以22的最简便的计...1/1乘以2乘以3+1/2乘以3乘以4+1/3乘以4乘以5…+1/20乘以21乘以22的最简便的计算方法 (2乘以10的负4次方)除以(5乘以10的9次方)= 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