5.26-0.72÷1.6-0.55=5.26-0.72÷0.8÷2-0.55=5.26-(0.9÷2+0.55)=5.26-(0.45+0.55)=5.26-1=4.26
5.26-0.72÷1.6-0.55=5.26-0.45-0.55=5.26-(0.45+0.55)=5.26-1=4.26