can you help me with this? thanks a lot

4. The following DEs are not separable, though they can be transformed into separable DEs under an appropriate change of variables. Find and perform the change of variables in order to solve the IVP. (a) xy' = y + x sec 9 ) , y(1) = 0 1 ( b ) y' = +1' 3 (0 ) = 0 (c) x (ydy - x dx) = y2 dx, y(1) = -5