17. Найди значение выражения (3√x + 2√y) / (9x - 4y) + 5√y, если √x + √y = 6.

Let $$a = \sqrt{x}$$ and $$b = \sqrt{y}$$. The expression becomes $$\frac{3a + 2b}{9a^2 - 4b^2} + 5b$$. We are given $$a+b=6$$. The denominator is a difference of squares: $$9a^2 - 4b^2 = (3a - 2b)(3a + 2b)$$. So the expression simplifies to $$\frac{1}{3a - 2b} + 5b$$. Without specific values for $$a$$ and $$b$$, the expression cannot be evaluated to a single numerical value. The problem statement might be incomplete or contain a typo.