1) $\frac{43}{12} = a + \frac{1}{b + \frac{1}{c + \frac{1}{d}}} \Rightarrow a + b + c + d = ?$

2) $\frac{1}{\sqrt{x} - \frac{1}{\sqrt{x} - \frac{1}{\dots}}} = a \Rightarrow \sqrt{x} - a = ?$

3) $\frac{x + 1}{3} = \frac{y - 1}{2} = \frac{z + 1}{4} , x + y + z = 17 \Rightarrow \frac{z}{x + y} = ?$

4) $\frac{xy}{x + y} = \frac{1}{9}, \frac{xz}{x + z} = \frac{1}{12}, \frac{yz}{y + z} = \frac{1}{15} \Rightarrow x + y + z = ?$

5) $\frac{y}{\sqrt{a}} = 11 \Rightarrow a - 2\sqrt{a} = ?$