Przekształcamy podane pierwiastki:

$\sqrt{169}+\frac{2}{3}\sqrt{27}=13+\frac{2}{3}\sqrt{3\cdot 9}=13+\frac{2}{3}\cdot 3\sqrt{3}=\underline{13+2\sqrt{3}}$

$\frac{1}{5}\sqrt{144}-\frac{1}{3}\sqrt{121}=\frac{1}{5}\cdot 12-\frac{1}{3}\cdot 11=\frac{12}{5}-\frac{11}{3}=\frac{36}{15}-\frac{55}{15}=-\frac{19}{15}$ $\frac{1}{5}\sqrt{144}-\frac{1}{3}\sqrt{121}=\frac{1}{5}\cdot 12-\frac{1}{3}\cdot 11=\frac{12}{5}-\frac{11}{3}=\frac{36}{15}-\frac{55}{15}=-\frac{19}{15}$

$\frac{3}{4}\sqrt{64}+\frac{2}{5}\sqrt{125}=\frac{3}{\sout{4}}\cdot \sout{8}+\frac{2}{5}\sqrt{25\cdot 5}=3\cdot 2+\frac{2}{5}\cdot 5\sqrt{5}=\underline{6+2\sqrt{5}}$

$6\sqrt{9}+3\sqrt{81}=6\cdot 3+3\cdot 9=18+27=45$

$-2\sqrt{256}+4\sqrt{16}=-2\cdot 16+4\cdot 4=-32+16=-16$

Liczby niewymierne:

$\sqrt{169}+\frac{2}{3}\sqrt{27}$

$\frac{3}{4}\sqrt{64}+\frac{2}{5}\sqrt{125}$