This is a question given to school students in the UK. Can /sci/

What's the matter? It's just the binomial theorem.

As aforementioned, just using the binomial theorem

>>7944900
This could be expressed so much more easily with factorials

>>7944900
>AEA
lol
nobody with 2 brain cells doing maths does that in the UK, and it's not really respectable
here's the usual kind of exams UK students take for entrance to some of the better unis:
https://googledrive.com/host/0B1ZiqBksUHNYMTZlRm1iQnJPTWs/Papers/2015%20STEP%203.pdf

>>7944900
>>7945675
How come the British teenagers can solve such mathematics? How come they're higher up than most of /sci/?

>>7945668
It is really ugly.

>>7945695
It's really not hard mathematics, it might look hard but most of the harder questions in STEP papers either have challenging geometry or you need to make some not-so-obvious factorization or substitution- both of which are skills that can be mastered, compared to Oxford's/Imperial's MAT which are honestly just there to test your aptitude.
Also, you'll find that most of the mathematicians at the higher unis in the UK are East Asian (Oxbridge, UCL, Imperial, Warwick, etc).

I forgot to mention you don't need to complete all questions to get a good grade... 4 questions in 3 hours will suffice.

Seems very difficult to me. I don't see how even (a) follows from the first formula. (b) seems easier.