3分之1÷9分之4+3分之1+4分之1
=1/3z9/4+1/3+1/4
=3/4+1/4+1/3
=1+1/3
=4/3
（8分之1+6分之1）÷24分之5 - 3分之2x4分之1
=(3/24+4/24)x24/5-1/6
=7/24x24/5-1/6
=7/5-1/6
=37/30