Initial Value Problem using Laplace

[kblank89]

Is this problem possible?

Solve the initial value problem

x''(t) + 6x'(t) + 9x(t) = f(t); x(0) = N, x'(0) = M

I get to

X(s)=(F(t)+Ns+6N+M)/(s^2+15)

and don't know where to go from here. Any help would be appreciated.

 

[JJacquelin]

I get to X(s)=(F(t)+Ns+6N+M)/(s^2+15)

It seems that there are several mistakes.
The Laplace transform of x(t) is X(s). With x(0) = N, x'(0) = M ,
what is the Laplace transform of x''(t) ?
what is the Laplace transform of x'(t) ?
what is the Laplace transform of f(t) ? ... it is not F(t).