The first time I did this problem I didn’t understand the question because I didn’t understand the subs teaching. The problem I had on my first attempt was that I didn’t simplify first before multiplying. I used Google image to do one of the problems you didn’t assign in that section and used the same strategy on this question. I needed to remember to simplify first before doing anything else. Next time I come across a problem that is difficult I will simplify before I try to start doing anything else.