楼上第二题错了
百分之37.5-3分之2*8分之3
=3/8-2/3x3/8
=(1-2/3)x3/8
=1/3x3/8
=1/8
0.75*8分之3+4分之1/3分之8
=3/4x3/8+1/4x3/8
=(3/4+1/4)x3/8
=1x3/8
=3/8
如果本题有什么不明白可以追问,