$\sqrt{12}\ast \sqrt{3}=\sqrt{12\ast 3}=\sqrt{36}=6$

$\sqrt{32}\ast \sqrt{2}=\sqrt{32\ast 2}=\sqrt{64}=8$

$\sqrt{18}\ast \sqrt{50}=\sqrt{18\ast 50}=\sqrt{900}=30$

$\sqrt{0,009}\ast \sqrt{1000}=\sqrt{0,009\ast 1000}=\sqrt{9}=3$

$\sqrt{200}\ast \sqrt{0,18}=\sqrt{200\ast 0,18}=\sqrt{36}=6$

$\sqrt{13}\ast \sqrt{2}\ast \sqrt{26}=\sqrt{13\ast 2\ast 26}=\sqrt{26\ast 26}=\sqrt{{26}^2}=|26|=26$

$\sqrt{2,4}\ast \sqrt{1\frac{2}{3}}=\sqrt{2,4\ast 1\frac{2}{3}}=\sqrt{\frac{24}{10}\ast \frac{5}{3}}=\sqrt{\frac{12}{5}\ast \frac{5}{3}}=\sqrt{\frac{4}{1}\ast \frac{1}{1}}=\sqrt{4}=2$

$\sqrt{\frac{2}{11}}\ast \sqrt{8}\ast \sqrt{\frac{1}{11}}=\sqrt{\frac{2}{11}\ast 8\ast \frac{1}{11}}=\sqrt{\frac{16}{{11}^2}}=\frac{4}{|11|}=\frac{4}{11}$

$\sqrt{2^3\ast 3}\ast \sqrt{2^5\ast 3^3}=\sqrt{2^3\ast 3\ast 2^5\ast 3^3}=\sqrt{2^{3+5}\ast 3^{1+3}}=\sqrt{2^8\ast 3^4}=\sqrt{2^8}\ast \sqrt{3^4}=\sqrt{(2^4{)}^2}\ast \sqrt{(3^2{)}^2}=|2^4|\ast |3^2|=|16|\ast |9|=144$