# Talk

## Expanding Polynomials - Year 9

(9 Posts)
thisagain Tue 03-May-16 20:35:30

Hi,
Does anyone know how to do this and what a polynomial is. My daughter got given her maths result from a test a few weeks ago and has another test (to set for GCSE tomorrow). She has been given a sheet today (!) saying what she didn't get full marks on, and this subject is on it so clearly needs to be worked on for tomorrow's test. She doesn't even know what a polynomial is! Having googled it, all we can find is information that is much more advanced than year 9. Is perhaps polynomial a different name for something that would mean something to her/us?

thecatfromjapan Tue 03-May-16 20:43:48

I'm guessing they mean multiplying out brackets:

(x^2 + 3) (x + 2)

Each term in bracket A has to multiply with each term in bracket B, and then you gather the terms together, simplifying where necessary.

So X^2 (in bracket A) has to multiply with x and then +2 (in bracket B), then +3 (in bracket A) needs to multiply with x and +2 (in bracket B).

Does this ring a bell with her?

thecatfromjapan Tue 03-May-16 20:45:01

I'm not a secondary maths teacher!! And I'm not good on the terminology. I'm basically bumping this for you. But does she think this is what she's been having problems with?

titchy Tue 03-May-16 20:45:59

I think it just mean expanding brackets, so

y = (x + 2)(x + 6)

So expanding:
y = xsquared + 6x + 2x + 12
y = xsquared + 8x + 12

thisagain Tue 03-May-16 20:55:21

Thanks. She can expand brackets so that's good if that is all it is. Also she has just realised that she actually lost marks on it just because it was at the end of the paper and had run out of time, rather than got the answers wrong so hopefully is fine on this really.

However, applied fraction calculations! Any idea what this is?. She got full marks on the adding/subtracting/multiplying and dividing fractions (so it doesn't mean that!) but got 0/3 for this.

noblegiraffe Tue 03-May-16 21:21:29

Applied fraction calculations probably just means a real life problem with fractions in. Something like 'John has to walk three and three quarter miles. He has already walked one and seven ninths of a mile, how far has he left to walk?'

thisagain Tue 03-May-16 21:37:31

I said that but she said that there were no wordy questions in it. Perhaps she was wrong though to be honest I would be surprised that she got 0/3 if that was the case! I'll ask her again though with your example to see if it rings bells.

booklooker Wed 04-May-16 09:34:35

Still working in miles, noble? Tut tut!

booklooker Wed 04-May-16 09:36:31

Actually, I have no idea if they are still on the Nat Cur. So apologies.

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