\(\sqrt{72} + \sqrt{32} - 3\sqrt{18} = x\sqrt{8}\) = \(\sqrt{36 \times 2} + \sqrt{16 \times 2} - 3\sqrt{2 \times 9}\) = x\(\sqrt{2 \times 4}\) = 6\(\sqrt{2} + 4\sqrt{2} - 9\sqrt{2} = 2 \times \sqrt{2}\) \(\sqrt{2} (6 + 4 - 9) = 2x\sqrt{2}\) \(\sqrt{2} = 2x \sqrt{2}\) divide both sides by \(\sqrt{2}\) \(\frac{\sqrt{2}}{\sqrt{2}} = \frac{ 2x\sqrt{2}}{\sqrt{2}}\) 1 = 2x 2x = 1 x = \(\frac{1}{2}\)