\[ y'(x)=\frac {x \sqrt {x^2+y(x)^2}+x^4 \sqrt {x^2+y(x)^2}+x^3 \sqrt {x^2+y(x)^2}+y(x)}{x} \] ✓ Mathematica : cpu = 0.0396985 (sec), leaf count = 26
\[\left \{\left \{y(x)\to x \sinh \left (c_1+\frac {x^4}{4}+\frac {x^3}{3}+x\right )\right \}\right \}\]
✓ Maple : cpu = 5.871 (sec), leaf count = 38
\[ \left \{ \ln \left ( y \left ( x \right ) +\sqrt { \left ( y \left ( x \right ) \right ) ^{2}+{x}^{2}} \right ) -{\frac {{x}^{4}}{4}}-{\frac {{x}^{3}}{3}}-x-\ln \left ( x \right ) -{\it \_C1}=0 \right \} \]