简便方法计算,急

问题描述:

简便方法计算,急
(3/5-1/2-7/12)乘(60*3/7-60*1/7+60*5/7)= 13除1.5-0.34除3又1/3+1/3除1/13-0.34除1又2/5= -149又3/40乘20= 99又24/25乘(-5)= 全部用简便方法计算!急,

(3/5-1/2-7/12)乘(60*3/7-60*1/7+60*5/7) =(3/5-1/2-7/12)乘(3/7-1/7+5/7)×60 =(3/5-1/2-7/12)×1×60 =3/5×60-1/2×60-7/12×60 =36-30-35 = -29 13除1.5-0.34除3又1/3+1/3除1/13-0.34除1又2/5 =13除3/2-0.3...