\[ A(x) \left (f(x) y''(x)+g(x) y'(x)+h(x) y(x)\right )+f'(x) y''(x)+f(x) y^{(3)}(x)+g'(x) y'(x)+g(x) y''(x)+y(x) h'(x)+h(x) y'(x)=0 \] ✗ Mathematica : cpu = 0.0332937 (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
\[ \left \{ y \left ( x \right ) ={\it DESol} \left ( \left \{ f \left ( x \right ) {\frac {{\rm d}^{3}}{{\rm d}{x}^{3}}}{\it \_Y} \left ( x \right ) + \left ( {\frac {\rm d}{{\rm d}x}}f \left ( x \right ) +g \left ( x \right ) +A \left ( x \right ) f \left ( x \right ) \right ) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}{\it \_Y} \left ( x \right ) + \left ( {\frac {\rm d}{{\rm d}x}}g \left ( x \right ) +h \left ( x \right ) +A \left ( x \right ) g \left ( x \right ) \right ) {\frac {\rm d}{{\rm d}x}}{\it \_Y} \left ( x \right ) + \left ( {\frac {\rm d}{{\rm d}x}}h \left ( x \right ) +A \left ( x \right ) h \left ( x \right ) \right ) {\it \_Y} \left ( x \right ) \right \} , \left \{ {\it \_Y} \left ( x \right ) \right \} \right ) \right \} \]