[SOLVED] Differential Equation Help

Hi all,

Earlier I started a thread with a past exam question that I wanted to understand before I attempted a homework question. It is similar to the question I posted earlier, but Im still having trouble with it.

Here it is:

"find the equation of R(t) when

where and ,

where and

and

where are all constants.

Now I know that

and then by substituting these values into we obtain

this is where I get lost. How do I continue from here? What type of differential equation is this? Thanks