(no subject)

[chess]

y/x + y/x+n = p is the general form of the annoying equation thing from the exam - knows are y, n and p, so x needs to be found in terms of y, n and p.

Comments

Solving the maths

[passage.livejournal.com]

I suspect you wrote that wrong because it simplifies to 2y/x + n = p
which gives n-p = 2y/x
taking the reciprocal: x/2y =1/(n-p)
To give: x=2y/(n-p)
Which is not hard
did you infact mean y/x + y/(x+n) =p
in which case y(2x+n)/x(x+n)=p (common denomiator)
Multiplying through by x(x+n)/y and exanding the bracket gives: 2x+n = px^2/y + npx/y
=> px^2/y+(npx/y -2)x-n = 0
Which looks nicer as:
px^2 + (npx-2y)x -n =0
Now, if you have numbers sub them in as it may facorise, else you'll have to solve that using quadratic formular (or completing the sqaure). Neith or which are too taxing, can you figure out the rest from here?

Neil

P.S.: If it was the first feel suitably embarressed, if it was the second then that is surprisingly hard for a GCSE paper, I could find A level students who couldn't do that (on the other thadn I know some throughly incometant A level mathematicians).

Re: Solving the maths

[marble.livejournal.com]

*sigh* There was a time I'd have been able to do that. (Well, I could probably still have done the bit you went through, but I haven't used the quadratic formula or completed the square since my A Level days, over 7 years ago...)

Re: Solving the maths

[passage.livejournal.com]

Actualy she had numbers which gave something that factorised nicely so you wouldn't have needed the knowledge (really poilt the question that, I was quite impressed with it for a while).

Neil, who can't really talk being as he's just discovered he can't do maths.