
Yefim S. answered 08/19/20
Math Tutor with Experience
y' = e3x + y;dy/dx = e3x·ey; e- ydy = e3xdx; ∫ e- ydy = ∫e3xdx; - e- y+ C = 1/3e3x; 1/ey = C - 1/3e3x;
ey = 1/(C - 1/3e3x); y = ln[1/(C- 1/3e3x)]; C is arbitrary constant.
So right answer is C.)