\[ -a y(x)^n-b x^{(m+1) n}+x^{m (n-1)+n} y'(x)=0 \] ✗ Mathematica : cpu = 300.016 (sec), leaf count = 0 , timed out
$Aborted
✓ Maple : cpu = 0.247 (sec), leaf count = 60
\[ \left \{ \int _{{\it \_b}}^{y \left ( x \right ) }\!-{\frac {{x}^{mn}{x}^{n}}{ \left ( b{x}^{m}x- \left ( m+1 \right ) {\it \_a} \right ) {x}^{n}{x}^{mn}+a{{\it \_a}}^{n}{x}^{m}x}}\,{\rm d}{\it \_a}+\ln \left ( x \right ) -{\it \_C1}=0 \right \} \]