[tex]\sqrt{45} \ *\sqrt{5} -\frac{\sqrt{75}}{\sqrt{27}}= \\\sqrt{45 \ * \ 5}-\frac{\sqrt{25 \ * \ 3}}{\sqrt{9 \ * \ 3}}=\\ \sqrt{225} - \frac{\sqrt{25} \ * \ \sqrt{3}}{\sqrt{9} \ * \ \sqrt{3}}=\\15 - \frac{5\sqrt{3}}{3\sqrt{3}}=\\15 - \frac{5}{3}=\\\frac{45}{3}-\frac{5}{3}=\\ \frac{40}{3}[/tex]
