①=18.9×(1-1÷1.4)+1.1=5.4+1.1=6.5 ②=0.25×4.8-7.5×0.25÷3=1.2-0.625=0.575
③=2.3×1.5+1.5×3÷0.75=1.5×(2.3+3÷0.75)=9.45 ④=12×12÷0.6-4.2×3=12×20-4.2×3=227.4
⑤=18.5-10.4÷1.3=18.5-8=10.5 ⑥=0.25×(2.2+2.8)=5×0.25=1.25
⑦=1.4×(45.9÷0.9)=1.4×51=71.4 ⑧=[2.5×(1-0.6)]÷0.4=1÷0.4=2.5
⑨=[2.5×0.9]×0.4=2.5×0.4×0.9=1×0.9=0.9