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Maths homework! HELP?

this is one of the question on my homework for core 4. im kinda suck. help please?

(edited 9 years ago)
Screenshot (9).png80.5KB
Reply 1
Avatar for Aillias
Aillias
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Where's the question?
Reply 2
Avatar for Alice Moody
Alice Moody
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Original post by Aillias
Where's the question?


on the screen shot above?
Could you post your working so far?

You can use the "given that" information to help you rewrite the fraction into two fractions. You can then rewrite each fraction separately into the required form for a binomial expansion and then go up to the x^3 term for both. Then add the two expansions together.
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Avatar for Alice Moody
Alice Moody
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Original post by rayquaza17
Could you post your working so far?

You can use the "given that" information to help you rewrite the fraction into two fractions. You can then rewrite each fraction separately into the required form for a binomial expansion and then go up to the x^3 term for both. Then add the two expansions together.


I havent done any working so far. i know what to do for the binomial expansion bit, its just finding A and B?? i get x=half, but the question says it doesnt......any ideas?
Original post by Alice Moody
I havent done any working so far. i know what to do for the binomial expansion bit, its just finding A and B?? i get x=half, but the question says it doesnt......any ideas?


Did you get 3x-1 = (1-2x)A + B
In this case, it is fine to sub in x=1/2 to find out the value of B.
Reply 6
Avatar for Alice Moody
Alice Moody
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Original post by rayquaza17
Did you get 3x-1 = (1-2x)A + B
In this case, it is fine to sub in x=1/2 to find out the value of B.


Thank you for your help, but i dont understand why its ok to use half, when its says you cant?

(for the record im not smart :wink: )
Original post by Alice Moody
Thank you for your help, but i dont understand why its ok to use half, when its says you cant?

(for the record im not smart :wink: )


I really don't know how to explain it/I don't 100% know myself why. Sorry :frown:

Maybe someone with more understanding can answer why this is ok to do??
Reply 8
Avatar for Alice Moody
Alice Moody
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Original post by rayquaza17
I really don't know how to explain it/I don't 100% know myself why. Sorry :frown:

Maybe someone with more understanding can answer why this is ok to do??


Ill do that, and if my teachers marks it wrong, ill ask why.

but thank you for your help!! :smile:
Reply 9
Avatar for 7253567
7253567
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If you don't want to sub in x=1/2, try using two other values of x and form simultaneous equations.


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Reply 10
Avatar for Aillias
Aillias
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Original post by Alice Moody
on the screen shot above?


Ah it didn't load the first time

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