Giúp e với ạ câu 59 ạ

$\text{ĐKXĐ: } x \ge 0, x \ne 9 \\ P = \frac{x + 7}{\sqrt{x}} + \frac{\sqrt{x} - 3}{\sqrt{x}} = \frac{x + \sqrt{x} + 5}{\sqrt{x}} - 2\sqrt{5} -1 + 2\sqrt{5} + 1 = \frac{x + \sqrt{x} + 5 - \sqrt{x}(2\sqrt{5} + 1)}{\sqrt{x}} + 2\sqrt{5} + 1 = \frac{x - 2\sqrt{5}\sqrt{x} + 5}{\sqrt{5}} + 2\sqrt{5} + 1 = \frac{(x - \sqrt{5})^2}{\sqrt{x}} + 2\sqrt{5} + 1 \ge 2\sqrt{5} + 1 \\ \text{Vậy } P_{min} = 2\sqrt{5} + 1 \Leftrightarrow x=\sqrt{5}$