7分之4比0.8
=4/7:0.8
=5:7
0.19比2.85
=19:285
=1:15
4分比40分之1小时
=4分:3/2分
=8:3
3分之2比1.2
=2/3:1.2
=5:9
3/4-9(1/5+1/3)*9/8
=3/4-9*8/15*9/8
=3/4-27/5
=15/20-108/20
=-93/20
7分之4比0.8 =4/7:8/10=40:56=5:7
0.19比2.85=19:285
4分比40分之1小时=4/60:1/40=160:60=8:3
3分之2比1.2=2/3:12/10=20:36=5:9
递等式
3/4-9
=3/4-36/4
=-33/4
(1/5+1/3)*9/8
=(3/15+5/15)*9/8
=8/15*9/8
=9/15
=3/5