\[ y'(x)=\frac {x \left (a y(x)^2+b x^2\right )^2}{a^{5/2} y(x)} \] ✓ Mathematica : cpu = 0.367267 (sec), leaf count = 117
\[\left \{\left \{y(x)\to -\sqrt {\frac {a^{3/4} \sqrt {b} \tan \left (\frac {a^{3/2} b x^2+2 c_1}{a^{9/4} \sqrt {b}}\right )-b x^2}{a}}\right \},\left \{y(x)\to \sqrt {\frac {a^{3/4} \sqrt {b} \tan \left (\frac {a^{3/2} b x^2+2 c_1}{a^{9/4} \sqrt {b}}\right )-b x^2}{a}}\right \}\right \}\]
✓ Maple : cpu = 0.461 (sec), leaf count = 460
\[ \left \{ y \left ( x \right ) ={\frac {1}{a}\sqrt {- \left ( {\it \_C1}\,{{\rm e}^{{\frac {{x}^{2}}{2} \left ( 2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}}+{{\rm e}^{{\frac {{x}^{2}}{2} \left ( -2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}} \right ) a \left ( \left ( b{x}^{2}-\sqrt {-{b{a}^{-{\frac {3}{2}}}}}{a}^{{\frac {3}{2}}} \right ) {{\rm e}^{{\frac {{x}^{2}}{2} \left ( -2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}}+{\it \_C1}\, \left ( \sqrt {-{b{a}^{-{\frac {3}{2}}}}}{a}^{{\frac {3}{2}}}+b{x}^{2} \right ) {{\rm e}^{{\frac {{x}^{2}}{2} \left ( 2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}} \right ) } \left ( {\it \_C1}\,{{\rm e}^{{\frac {{x}^{2}}{2} \left ( 2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}}+{{\rm e}^{{\frac {{x}^{2}}{2} \left ( -2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}} \right ) ^{-1}},y \left ( x \right ) =-{\frac {1}{a}\sqrt {- \left ( {\it \_C1}\,{{\rm e}^{{\frac {{x}^{2}}{2} \left ( 2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}}+{{\rm e}^{{\frac {{x}^{2}}{2} \left ( -2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}} \right ) a \left ( \left ( b{x}^{2}-\sqrt {-{b{a}^{-{\frac {3}{2}}}}}{a}^{{\frac {3}{2}}} \right ) {{\rm e}^{{\frac {{x}^{2}}{2} \left ( -2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}}+{\it \_C1}\, \left ( \sqrt {-{b{a}^{-{\frac {3}{2}}}}}{a}^{{\frac {3}{2}}}+b{x}^{2} \right ) {{\rm e}^{{\frac {{x}^{2}}{2} \left ( 2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}} \right ) } \left ( {\it \_C1}\,{{\rm e}^{{\frac {{x}^{2}}{2} \left ( 2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}}+{{\rm e}^{{\frac {{x}^{2}}{2} \left ( -2\,\sqrt {-{\frac {b}{{a}^{3/2}}}}{a}^{3/2}+b{x}^{2} \right ) {a}^{-{\frac {3}{2}}}}}} \right ) ^{-1}} \right \} \]