原式=0.25*（4.8-2.5）=0.25*2.3=0.575
解.原式=0.25*（4.8-2.5）=0.25*2.3=0.25*2+0.25*3=0.5+0.75=1.25
1/4(4,8-7.5/3)=(4,8-2,5)/4=0.56
