Problem 4. Find the general solutions of the following differential equations. (10 points total) a. x d V dy +x- d'y dx +(x-ly =0 b. x +x- dx dy + (x2 - 90=0 c. x dy +x - +(x + 0)y=0 d. "d' y dy dx + x- (x2 +ly =0 exdy dy dx + x- chy-2 dx (x2 + 9)y =0 f.x2 dy + x da-2 dx (x2 + 0) y = 0