\[ \boxed { \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+ \left ( x+a \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) -y \left ( x \right ) =0} \]
Mathematica: cpu = 0.004501 (sec), leaf count = 18 \[ \left \{\left \{y(x)\to a c_1+c_1 x+c_1^2\right \}\right \} \]
Maple: cpu = 0.452 (sec), leaf count = 32 \[ \left \{ y \left ( x \right ) =-{\frac {{x}^{2}}{4}}-{\frac {ax}{2}}-{ \frac {{a}^{2}}{4}},y \left ( x \right ) ={{\it \_C1}}^{2}+{\it \_C1}\,a +{\it \_C1}\,x \right \} \]