Hi Jake (and whoever else reads this),
Just to get straight to the point,
I don't quite understand the answer to this binomial question (Taken from CSSA Trial 2012)
(Image attached, because I don't know how to paste it into this textbox LMAO much technology yay)
And alsoooo,
Isn't it so much easier to just belt out factorial notation, and slay LHS=RHS
Hey Zoe,
First of all, your description of a potential method of answering this question is absolutely gold. Keep at it, love your work.
Your method, and the method in the answers, is actually the same. If you do what you were planning on doing, that's great, but you would have to equate coefficients as there isn't another way to compare the RHS to the LHS and prove that they are equal. So, you would equate coefficients, and get exactly the same answer as they did. They're answer probably isn't comprehensive enough anyway; if your method gets you the right relationship, you're absolutely doing the right thing.
If you wanted a more comprehensive proof, though, let us know, however as far as I can tell your "do shit get marks" methodology is spot on.
Jake