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C4 Algebra Help

Hi
Im doing a c4 paper (link: http://www.mei.org.uk/files/papers/c408ju_op58.pdf)
This is kind of strange because it is supposedly the easiest question, yet i cant figure out how the mark scheme has simplified the fraction??

it's : " express x/(x^2-4) + 2/x+2 as a single fraction"
I have simplified the denominator of the first fraction by factorising it. I just cant figure the next 2 steps. The mark scheme isnt set out clearly

Help??

Thanks
Well what did you get when you factorised the denominator of the first term? :smile:

To express it as a single fraction, it must have a common denominator with the second term.

So what could you multiply the numerator and denominator of the second term by to give it the same denominator as the first term?
Reply 2
Avatar for B_9710
B_9710
18
xx2−4≡x(x+2)(x−2) \displaystyle \frac{x}{x^2-4} \equiv \frac{x}{(x+2)(x-2)} .
Reply 3
Avatar for Zacken
Zacken
22
Original post by starwarsjedi123
Hi
Im doing a c4 paper (link: http://www.mei.org.uk/files/papers/c408ju_op58.pdf)
This is kind of strange because it is supposedly the easiest question, yet i cant figure out how the mark scheme has simplified the fraction??

it's : " express x/(x^2-4) + 2/x+2 as a single fraction"
I have simplified the denominator of the first fraction by factorising it. I just cant figure the next 2 steps. The mark scheme isnt set out clearly

Help??

Thanks


Remember how to add fractions? 12+14=1×22×2+14=24+14=34\frac{1}{2} + \frac{1}{4} = \frac{1\times 2}{2 \times 2} + \frac{1}{4} = \frac{2}{4} + \frac{1}{4} = \frac{3}{4}.

Here it's:

xx2−4+2x+2=x(x−2)(x+2)+2x+2=x(x−2)(x+2)+2×(x−2)(x+2)(x−2)=⋯\displaystyle \frac{x}{x^2 -4 } + \frac{2}{x+2} = \frac{x}{(x-2)(x+2)} + \frac{2}{x+2} = \frac{x}{(x-2)(x+2)} + \frac{2 \times (x-2)}{(x+2)(x-2)} = \cdots
thanks guys + zacken :smile:

*close thread*
Reply 5
Avatar for Zacken
Zacken
22
Original post by starwarsjedi123
thanks guys + zacken :smile:

*close thread*


Wait, why am I not a guy? :laugh:
Original post by starwarsjedi123
thanks guys + zacken :smile:

*close thread*


If the thread is closed, no one will be able to bump it in a few months time. :cry2:
Original post by Zacken
Wait, why am I not a guy? :laugh:


rekt :rofl:

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