\[ y''(x)=\frac {y(x)}{f(x)}-\frac {x y'(x)}{f(x)} \] ✓ Mathematica : cpu = 0.0775299 (sec), leaf count = 46
\[\left \{\left \{y(x)\to c_2 x \int _1^x\frac {\exp \left (-\int _1^{K[2]}\frac {K[1]}{f(K[1])}dK[1]\right )}{K[2]^2}dK[2]+c_1 x\right \}\right \}\] ✓ Maple : cpu = 0.075 (sec), leaf count = 30
\[\left \{y \left (x \right ) = \left (c_{1} \left (\int {\mathrm e}^{\int \frac {-\frac {x^{2}}{f \left (x \right )}-2}{x}d x}d x \right )+c_{2}\right ) x\right \}\]