## Calculus with Applications (10th Edition)

$7\sqrt{2}$
Simplify each radical, when needed, to have: $=7\sqrt{2}-8\sqrt{9(2)} + 4\sqrt{36(2)} \\=7\sqrt{2} - 8\cdot 3\sqrt{2} + 4\cdot 6\sqrt{2} \\=7\sqrt{2} - 24\sqrt{2} + 24\sqrt{2}$ Combine like terms to have: $=(7-24+24)\sqrt{2} \\=7\sqrt{2}$