First solve the homogeneous equation .

The characteristic equation is .

Thus, the complimentary solution is .

Now, let and .

We now need to find and

Thus,

I leave it for you to find (See spoiler to check your answer).

Spoiler:

Thus,

I leave it for you to find (See spoiler to check your answer).

Spoiler:

Once you find and , the solution to your differential equation would be (See spoiler to check your answer)

Spoiler: