5/6+3/4-1/3= 10/12+9/12-4/12 = 15/12 = 5/4 (读作:四分之五)
4/5+7/10-13/20= 16/20 + 14/20 -13/20 = 17/20 (读作:二十分之十七)
7/8-5/12+1/6= 21/24 - 10/24 + 4/24 = 15/24 = 5/8 (读作:八分之五)
6/5+4/3-3/1
=18/15+20/15-45/15
=-7/15
5/4+10/7-20/13
=455/364+520/364-560/364
=415/364
8/7-12/5+6/1
=40/35-84/35+11760/35
=11716/35
《精》 原式=6/5+(4/3-1/3)=6/5+1=11/5
《锐》 原式=(5×91+10×52-20×50)/(4×7×13) =5×(91+104-200)/(4×7×13)=5×(-5)/364=-25/364
原式=1+1/7+6-2-2/5=5+1/7-2/5=5-9/35=166/35
13/15 315/234 简单麻烦