$\text{a)}\sqrt{1\frac{11}{25}}=\sqrt{\frac{36}{25}}=\frac{\sqrt{36}}{\sqrt{25}}=\frac{6}{5}=1\frac{1}{5}$  

Sprawdzenie: 

$1\frac{1}{5}\cdot 1\frac{1}{5}=\frac{6}{5}\cdot \frac{6}{5}=\frac{36}{25}=1\frac{11}{25}$  

 

$\text{b)}\sqrt{5\frac{4}{9}}=\sqrt{\frac{49}{9}}=\frac{\sqrt{49}}{\sqrt{9}}=\frac{7}{3}=2\frac{1}{3}$  

Sprawdzenie: 

$2\frac{1}{3}\cdot 2\frac{1}{3}=\frac{7}{3}\cdot \frac{7}{3}=\frac{49}{9}=5\frac{4}{9}$  

 

$\text{c)}\sqrt{3\frac{13}{36}}=\sqrt{\frac{121}{36}}=\frac{\sqrt{121}}{\sqrt{36}}=\frac{11}{6}=1\frac{5}{6}$  

Sprawdzenie: 

$1\frac{5}{6}\cdot 1\frac{5}{6}=\frac{11}{6}\cdot \frac{11}{6}=\frac{121}{36}=3\frac{13}{36}$