[tex]a] \ \frac{4}{\sqrt2}\cdot\frac{\sqrt2}{\sqrt2}=\frac{4\sqrt2}{\sqrt{2^2}}=\frac{4\sqrt2}{2}=2\sqrt2\\\\b] \ \frac{6}{\sqrt3}\cdot\frac{\sqrt3}{\sqrt3}=\frac{6\sqrt3}{\sqrt{3^2}}=\frac{6\sqrt3}{3}=2\sqrt3\\\\c] \ \frac{2}{3\sqrt2}\cdot\frac{\sqrt2}{\sqrt2}=\frac{2\sqrt2}{3\sqrt{2^2}}=\frac{2\sqrt2}{3\cdot2}=\frac{\sqrt2}{3}\\\\d] \ \frac{3}{5\sqrt3}\cdot\frac{\sqrt3}{\sqrt3}=\frac{3\sqrt3}{5\sqrt{3^2}}=\frac{3\sqrt3}{5\cdot3}=\frac{\sqrt3}{5}[/tex]
