96乘以93分之19和5分之3乘以7加0.6乘以4-5分之3的簡便方法

96乘以93分之19和5分之3乘以7加0.6乘以4-5分之3的簡便方法


96×(19/93)=(93+3)×(19/93)=19+19/31=19又19/31(3/5)×7+0.6×4-(3/5)=0.6×(7+4-1)=0.6×10=6



1994乘以1994减去1993乘以1995分之1994怎麼巧算
1994乘以1994减去1993乘以1995是分母


答:樓主請注明一下哪個是分子哪個是分母?新增括弧好理解,
1994乘以1994减去1993乘以1995分之1994
(補充說明中:1994乘以1994减去1993乘以1995是分母)
=1994/(1994×1994-1993×1995)
=1994/[1994×1994-(1994-1)×(1994+1)]
=1994/[1994²;-(1994²;-1)]
=1994/1
=1994



3.6×25.4+37.9×6.4
這是一道奧數題
用乘法分配率


3.6×25.4+37.9×6.4
=3.6×25.4+(25.4+12.5)×6.4
=3.6×25.4+25.4×6.4+12.5×6.4
=3.6×25.4+25.4×6.4+12.5×8×0.8
=25.4×(3.6+6.4)+100×0.8
=254+80
=334



2/3减去1/4的差乘20/21的倒數,積是多少?


(2/3-1/4)*21/20=(5*21)/(12*20)
上下約分=7/16