计算,（1）54又2/5除以17 （2）1/2+1/6+1/12+1/20+1/30+1/42
问题描述：
计算,（1）54又2/5除以17 （2）1/2+1/6+1/12+1/20+1/30+1/42
答
(1)原式=(54*5+2)/5/17=272/5/17=16/5 (2)原式=30/60+10/60+5/60+3/60+2/60=(30+10+5+3+2)/60=50/60=5/6
答
（1）54又2/5除以17
54又2/5÷17
=272/5÷17
=16/5
=3又1/5
（2）1/2+1/6+1/12+1/20+1/30+1/42
=30/60+10/60+5/60+3/60+2/60+1/42
=50/60+1/42
=5/6+1/42
=35/42+1/42
=36/42
=6/7