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Help Edexcel C3 Maths Algebraic fractions

Somebody please explain to me where to go on Edexcel book C3 Ex1E, Q4. I've got up to x^3+2x^2-3/(x+3)(x-1). I just don't know how to further simplify this.
Original post by jamb97
Somebody please explain to me where to go on Edexcel book C3 Ex1E, Q4. I've got up to x^3+2x^2-3/(x+3)(x-1). I just don't know how to further simplify this.


Factorise the numerator first.
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Original post by Dingooose
Factorise the numerator first.
How? I tried and got x(x^2+2x)-3 for the numeator please help
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SH0405
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Original post by jamb97
How? I tried and got x(x^2+2x)-3 for the numeator please help


Notice that x=1 is a solution to x3+2x2-3=0.
(edited 8 years ago)
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Original post by SH0405
Notice that x=1 is a solution to x3+2x2-3=0.
That makes sense now but I couldn't spot that, is that something you're taught or is it like a common sense kinda thing?
Original post by jamb97
That makes sense now but I couldn't spot that, is that something you're taught or is it like a common sense kinda thing?


It's a bit of both. And now you can use that fact and turn x3+2x2−3x^3+2x^2-3 into (x−1)(x2+bx+c)(x-1)(x^2+bx+c). What are "b" and "c"? You can use algebraic division or trial and error to work those out.
(edited 8 years ago)
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SH0405
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Original post by jamb97
That makes sense now but I couldn't spot that, is that something you're taught or is it like a common sense kinda thing?


Sort of in between. It's always something to look out for.

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