\[ \boxed { {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +ay \left ( x \right ) -b\sin \left ( cx \right ) =0} \]
Mathematica: cpu = 0.058507 (sec), leaf count = 40 \[ \left \{\left \{y(x)\to \frac {b (a \sin (c x)-c \cos (c x))}{a^2+c^2}+c_1 e^{-a x}\right \}\right \} \]
Maple: cpu = 0.015 (sec), leaf count = 37 \[ \left \{ y \left ( x \right ) ={{\rm e}^{-ax}}{\it \_C1}+{\frac {b \left ( \sin \left ( cx \right ) a-c\cos \left ( cx \right ) \right ) }{{a }^{2}+{c}^{2}}} \right \} \]
Sage: cpu = 0.008 (sec), leaf count = 0 \[ \left [-{\left (\frac {{\left (c \cos \left (c x\right ) - a \sin \left (c x\right )\right )} b e^{\left (a x\right )}}{a^{2} + c^{2}} - c\right )} e^{\left (-a x\right )}, \text {\texttt {linear}}\right ] \]