[tex]\bf \sqrt{180}-\sqrt{125}+\sqrt{5}\qquad
\begin{cases}
180=2\cdot 2\cdot 3\cdot 3\cdot 5\\
\qquad 2^2\cdot 3^2\cdot 5\\
\qquad (2\cdot 3)^2\cdot 5\\
\qquad 6^2\cdot 5\\
125=5\cdot 5\cdot 5\\
\qquad 5^2\cdot 5
\end{cases}
\\\\\\
\sqrt{6^2\cdot 5}-\sqrt{5^2\cdot 5}+\sqrt{5}\implies 6\sqrt{5}-5\sqrt{5}+\sqrt{5}\implies 2\sqrt{5}[/tex]
