6+√6 5.a)/30+√5 ; б) 9-a 3+√a

5. Упростите выражение:

a) $$\frac{6+\sqrt{6}}{\sqrt{30} + \sqrt{5}} = \frac{6+\sqrt{6}}{\sqrt{5}(\sqrt{6} + 1)} = \frac{\sqrt{6}(\sqrt{6}+1)}{\sqrt{5}(\sqrt{6} + 1)} = \frac{\sqrt{6}}{\sqrt{5}} = \sqrt{\frac{6}{5}} = \frac{\sqrt{30}}{5}$$

Ответ: $$\frac{\sqrt{30}}{5}$$

б) $$\frac{9-a}{3+\sqrt{a}} = \frac{(3-\sqrt{a})(3+\sqrt{a})}{3+\sqrt{a}} = 3 - \sqrt{a}$$

Ответ: $$3-\sqrt{a}$$