"Given thatvandware vectors such thatvxw= 2i-j+ 3k, find:

(v+ 3w) x (2w-v)"

My working:

-> 2(vxw) -3(wxv)

Having a look at the solution, the equation needs to be further simplified: as 5(vxw) and what I do not understand is how you would be able to get to that equation. I understand the working out from after having simplified the equation - it is just this step of the answer that I am having difficulty with.