\[ a x^n f\left (y'(x)\right )+x y'(x)-y(x)=0 \] ✗ Mathematica : cpu = 299.999 (sec), leaf count = 0 , timed out
$Aborted
✓ Maple : cpu = 4.12 (sec), leaf count = 169
\[ \left \{ [y \left ( {\it \_T} \right ) =a \left ( \left ( {\frac {1}{f \left ( {\it \_T} \right ) na} \left ( \left ( 1-n \right ) \int \! \left ( f \left ( {\it \_T} \right ) \right ) ^{-{n}^{-1}}\,{\rm d}{\it \_T}+{\it \_C1}\,an \right ) } \right ) ^{ \left ( n-1 \right ) ^{-1}} \left ( f \left ( {\it \_T} \right ) \right ) ^{{\frac {1}{n \left ( n-1 \right ) }}} \right ) ^{n}f \left ( {\it \_T} \right ) +{\it \_T}\, \left ( {\frac {1}{f \left ( {\it \_T} \right ) na} \left ( \left ( 1-n \right ) \int \! \left ( f \left ( {\it \_T} \right ) \right ) ^{-{n}^{-1}}\,{\rm d}{\it \_T}+{\it \_C1}\,an \right ) } \right ) ^{ \left ( n-1 \right ) ^{-1}} \left ( f \left ( {\it \_T} \right ) \right ) ^{{\frac {1}{n \left ( n-1 \right ) }}},x \left ( {\it \_T} \right ) = \left ( {\frac {1}{f \left ( {\it \_T} \right ) na} \left ( \left ( 1-n \right ) \int \! \left ( f \left ( {\it \_T} \right ) \right ) ^{-{n}^{-1}}\,{\rm d}{\it \_T}+{\it \_C1}\,an \right ) } \right ) ^{ \left ( n-1 \right ) ^{-1}} \left ( f \left ( {\it \_T} \right ) \right ) ^{{\frac {1}{n \left ( n-1 \right ) }}}] \right \} \]