Last week I explained how to multiply binomials, but now we will be multiplying with trinomials, with a larger amount of terms this can start to become confusing using FOIL, so I will show you how to break it down step by step. This has a few steps that you have to follow, however if you want to get the right answer its best to follow them at first, at least until you get the hang of the shortcuts. I have given you an example of an equation down below and I have gone through what all the steps in the photo. First you will FOIL but on each side of the subtraction side, making sure all the numbers get factored with each other once, next you will  you will combine like terms then you will multiply by the original co-efficient and the combine like terms again (terms with the same variables) then you will combine both halves of the equation.

4(a-4)(-3a-6)-(4a-3)(4a+3)