# 2.&nbsp; Which ONE of the following is a linea...

2.  Which ONE of the following is a linear non-homogeneous differential equation, where x and y are the independent and dependent variables respectively?

(A) ${dy\over dx}+xy=e^{-x}$

(B) ${dy\over dx}+xy=0$

(C) ${dy\over dx}+xy=e^{-y}$

(D) ${dy\over dx}+e^{-y}=e^{-y}=0$

Hint: