[tex]3\sqrt{\frac{1}{27} } *9\frac{3}{2} =3\sqrt{\frac{1}{27} } *\frac{21}{2} =\sqrt{9*\frac{1}{27} } *\sqrt{\frac{21^2}{2^2} } =\sqrt{\frac{1}{3}*\frac{441}{4} } =\sqrt{\frac{147}{4} } =\frac{\sqrt{147} }{2}[/tex]
