3×1/2+1/2÷2×1/7=1又1/2+1/4×1/7=1又1/2+1/28=1又15/28(3/5-1/3)÷4/5÷12.5%=4/15÷4/5÷1/8=1/3÷1/8=2又2/3(3/4×75%+3/4×25%)÷7/6=3/4×(75%+25%)÷7/6=3/4÷7/6=9/145/3-2/5×4/3÷1/4=5/3-3/10÷1/4=5/3-6/5=7/15
得3又32分之5