Câu trả lời:
b, x-y+\(\sqrt{xy^2}\)-y\(^3\) =(x-y)+(\(\sqrt{xy^2}\)-\(\sqrt[3]{y^3}\)). =(\(\sqrt{x}\)-\(\sqrt{y}\))(\(\sqrt{x}\)+\(\sqrt{y}\))+\(\sqrt{y^2}\)(\(\sqrt{ }x\)-\(\sqrt{y}\)). =(\(\sqrt{x}\)-\(\sqrt{y}\))(\(\sqrt{x}\)+\(\sqrt{y}\)+\(\sqrt{y^2}\)). =(\(\sqrt{x}\)-\(\sqrt{y}\))(\(\sqrt{x}\)+\(\sqrt{y}\)+y) (vì y>0).