0.625:3/4=5/8:3/4=5/8x4/3=5/6请问八分之五怎么来的？还有，0.3:0.18=多少？求比值0.625=5/8或者这样算0.625:3/4=0.625:0.75=625:750=5:6=5/60.3:0.18=30:18=5:3=5/3