(1) 3 2 - 13 14 = 4 7 答:差是 4 7 .(2)(12+13)÷(13-12)=25÷1=25答:商是25.(3)(125-125×12%)×311=(125-15)×311=110×311=34210答:积是3421.(4)(5.3×4)÷(25×8)=21.2÷200=0.106答:结果是0.106.