[tex]\bf 3\sqrt{18}+2\sqrt{50}\qquad
\begin{cases}
18=2\cdot 3\cdot 3\\
\qquad 2\cdot 3^2\\
50=2\cdot 5\cdot 5\\
\qquad 2\cdot 5^2
\end{cases}\implies 3\sqrt{2\cdot 3^2}+2\sqrt{2\cdot 5^2}
\\\\\\
3\cdot 3\sqrt{2}+2\cdot 5\sqrt{2}\implies 9\sqrt{2}+10\sqrt{2}\implies 19\sqrt{2}[/tex]