简化后是这样，你再用计算机算49.8+8÷9+1÷7÷5÷8÷7÷6÷8
1+2*3+4/5+6*7+8/9+10/7/5/5/6/9/8/7/4/5/6/1/2/5/7/8/7/8 = 50.688888888894
50.688899518141
