[tex]2 \sqrt{18} +3 \sqrt{8} +3 \sqrt{32} - \sqrt{50} =2 \cdot 3 \sqrt{2} +3 \cdot 2 \sqrt{2} +3 \cdot 4 \sqrt{2} -5 \sqrt{2} = \\ =6 \sqrt{2} +6 \sqrt{2} +12 \sqrt{2} -5 \sqrt{2} =12 \sqrt{2} +12 \sqrt{2} -5 \sqrt{2} = \\ =24 \sqrt{2} -5 \sqrt{2} =19 \sqrt{2} [/tex]