The equation given is a one variable equation, "p".
The question asks to find the value of "p", which is the pounds of peanuts.
So, we need to solve the euqation for "p".

First, we need to put all the terms that have "p" in one side. For this, we will have to use the distributive property in the parenthesys first:

Now, we can substract 4.05p in both sides to get the "p" term of the left to the right:

Now, we do the same for the 13.50, substract it in both sides:

Now, we can divide both sides by 0.45:

So, the answer is p = 2, thus, you need 2 pounds of peanuts for the trail mix.