\[ A(x) \left (f(x) y''(x)+g(x) y'(x)+h(x) y(x)\right )+f'(x) y''(x)+f(x) y^{(3)}(x)+g'(x) y'(x)+g(x) y''(x)+y(x) h'(x)+h(x) y'(x)=0 \] ✗ Mathematica : cpu = 0.0253404 (sec), leaf count = 0 , could not solve
DSolve[y[x]*Derivative[1][h][x] + h[x]*Derivative[1][y][x] + Derivative[1][g][x]*Derivative[1][y][x] + g[x]*Derivative[2][y][x] + Derivative[1][f][x]*Derivative[2][y][x] + A[x]*(h[x]*y[x] + g[x]*Derivative[1][y][x] + f[x]*Derivative[2][y][x]) + f[x]*Derivative[3][y][x] == 0, y[x], x]
✗ Maple : cpu = 0. (sec), leaf count = 0 , result contains DESol
\[\{y \left (x \right ) = \mathit {DESol}\left (\left \{\left (\frac {d^{3}}{d x^{3}}\textit {\_Y} \left (x \right )\right ) f \left (x \right )+\left (A \left (x \right ) h \left (x \right )+\frac {d}{d x}h \left (x \right )\right ) \textit {\_Y} \left (x \right )+\left (A \left (x \right ) g \left (x \right )+\frac {d}{d x}g \left (x \right )+h \left (x \right )\right ) \left (\frac {d}{d x}\textit {\_Y} \left (x \right )\right )+\left (A \left (x \right ) f \left (x \right )+\frac {d}{d x}f \left (x \right )+g \left (x \right )\right ) \left (\frac {d^{2}}{d x^{2}}\textit {\_Y} \left (x \right )\right )\right \}, \left \{\textit {\_Y} \left (x \right )\right \}\right )\}\]