[tex]5 \sqrt{18} - \sqrt{32} \\= 5 \sqrt{9 \times 2} - \sqrt{4 \times 4 \times 2} \\ = 5 \times 3 \times \sqrt{2} - 2 \times 2 \times \sqrt{2} \\ = 15 \sqrt{2} - 4 \sqrt{2} \\ = \boxed{11 \sqrt{2} }[/tex]
