[47-(18.75-1/8/15)*2又6/25]/0.46

[47-(18。75-1÷15/8)×2又25/6]÷0。46 =[47-(75/4-15/8)×56/25]x50/23=[47-(75/4×56/25-15/8x56/25)]x50/23=[47-42+21/5]x50/23=46/5x50/23=20