\[ f(x) = \begin{cases} x^2 + 3, & \text{if } x \neq 0, \\ 1, & \text{if } x = 0. \end{cases} \]
Solve the following system of equations using matrices: \[ \frac{2}{x} + \frac{3}{y} + \frac{10}{z} = 4, \quad \frac{4}{x} - \frac{6}{y} + \frac{5}{z} = 1, \quad \frac{6}{x} + \frac{9}{y} - \frac{20}{z} = 2, \] where \( x, y, z \neq 0 \).
\[ \frac{dy}{dx} = \frac{y}{x}. \]