38×1.25+15÷80%-1.25×27
=38×1.25+15*1.25-1.25×27
=1.25(38+15-27)
=1.25*26
=5/4*(24+2)
=5/4*24+5/4*2
=30+2.5
=32.5
8分之1×58+8分之1×41+8分之1
=1/8*(58+41+1)
=1/8*100
=12.5
5分之4×7分之4×4分之5-2分之1
=(4/5*5/4)*4/7-1/2
=4/7-1/2
=8/14-7/14
=1/14
5分之4×6分之5+5分之2÷5分之3
=4/5*5/6+2/5*5/3
=2/3+2/3
=4/3
5分之4÷【（8分之5-2分之1）÷8分之5】
=(4/5)/[(1/8)*(8/5)]
=(4/5)/(1/5)
=4