5.87/0.25/0.587=5.87/0.587/0.25=10/0.25=（10*4）/（0.25*4）=40 117.3/0.46 = 255 20.03-17.308 =2.722 （12.6-5.1）*2.4-8.3=7.5*2.4-8.3=（2.5*4）*（3*0.6）-8.3=10*1.8-8.3=18-8.3=9.7
