What, you can't do that ? o.O

The LHS integrates to , the RHS integrates to

Try something like ...b) Use a suitable trial function to find one simple particular solution of dy/dx + 5y = 3e^(-9x)

Use the above.c) Find the solution of dy/dx + 5y = 3e^(-9x) that satisfies y(0) = -27/4.

Cheers...