Answer:
[tex] \sqrt[3]{ \frac{ {b}^{4} }{27b} } = \sqrt[3]{ \frac{b( {b}^{3}) }{27b} } \\ \\ \\ \sqrt[3]{ \frac{ {b}^{3} }{27} } = \frac{ \sqrt[3]{ {b}^{3} } }{ \sqrt[3]{27} } \\ \\ \\ = \frac{b}{3} [/tex]
I hope I helped you^_^
