You did it so fast without doing calculations unlike your other videos and that's why it was complicating yesterday. Today my it's more clear but still complicating, Hopefully, I get it easier by watching again and again. I would appreciate it if you make a similar video to this more slowly Edit; 1 week later: I am so good at it now
He said you need to takeaway the a term squared. I find it easier if you just make a one step equation. So do 9 = b + 4 and you get b = 5 rather than what he does.
literally it was that one occasion where the coefficient infront of the x^2 term was greater than 1 that confused me. Now, I literally dont have a weakness in maths and easy grade9 at gcse maths and further maths. Cant wait to do the papers