(1)(4.35-3.65)÷(4.35+3.65)=0.7÷8=0.0875答:结果是0.0875.(2)90.3÷(10.2-1.2×5)=90.3÷(10.2-6)=90.3÷4.2=21.5答:商是21.5.(3)90.3÷[10.2+(5.6-2.9)]=90.3÷[10.2+2.7]=90.3÷12.9=7答:商是7.(4)(37+23)×(3.6-2.8)=60×0.8=48答:积是48.