Упростим выражение: $$\frac{\sqrt{98} + \sqrt{150} \cdot \sqrt{6} - \sqrt{7^4 \cdot 3^2}}{\sqrt{2}}$$.
$$\frac{\sqrt{98} + \sqrt{150} \cdot \sqrt{6} - \sqrt{7^4 \cdot 3^2}}{\sqrt{2}} = \frac{\sqrt{49 \cdot 2} + \sqrt{25 \cdot 6} \cdot \sqrt{6} - \sqrt{(7^2)^2 \cdot 3^2}}{\sqrt{2}} = \frac{7\sqrt{2} + 5\sqrt{6} \cdot \sqrt{6} - 7^2 \cdot 3}{\sqrt{2}} = \frac{7\sqrt{2} + 5 \cdot 6 - 49 \cdot 3}{\sqrt{2}} = \frac{7\sqrt{2} + 30 - 147}{\sqrt{2}} = \frac{7\sqrt{2} - 117}{\sqrt{2}} = \frac{7\sqrt{2}}{\sqrt{2}} - \frac{117}{\sqrt{2}} = 7 - \frac{117\sqrt{2}}{2}$$.
Ответ: $$7 - \frac{117\sqrt{2}}{2}$$