1375+450除15乘25
=1375+30x5
=1375+750
=2125
9分之4除【5分之4-(5分之1+3分之1)]
=4/9÷(4/5-1/5-1/3)
=4/9÷(3/5-1/3)
=4/9÷4/15
=5/3
如果本题有什么不明白可以追问,