P2 Algebraic Fractions...Help Please!

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Emz
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#1
Report Thread starter 17 years ago
#1
Hi everyone!
Im having a total mind blank on simplifying this, I cant quite get it so if anyone could solve this showing the steps Id be eternally grateful!

x+1/2x-1 - x-1/2x+1 + 3/4x^2-1

Btw, the answer is 3/2x-1.

Thanks in advance for your help.

Emma xxx :cool:
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theone
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You need to get everything over the lowest common denominator, which in this case is 4x^2 - 1. Try doing this...
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mensandan
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(Original post by Emz)
Hi everyone!
Im having a total mind blank on simplifying this, I cant quite get it so if anyone could solve this showing the steps Id be eternally grateful!

x+1/2x-1 - x-1/2x+1 + 3/4x^2-1

Btw, the answer is 3/2x-1.

Thanks in advance for your help.

Emma xxx :cool:
Factorise last one:

(x+1)/(2x-1) - (x-1)/(2x+1) + 3/(2x-1)(2x+1)

Multiply through by (2x-1)(2x+1) and put in common denominator:

((x+1)(2x+1) - (x-1)(2x-1) + 3/(2x-1)(2x+1)

(2x^2 + 2x + x +1 - (2x^2 - 2x - x +1) + 3)/(2x + 1)(2x-1)

(6x+3)/(2x+1)(2x-1)

(3(2x+1))/(2x+1)(2x-1)

3/(2x-1)

Oh yeah!!!
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Emz
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Report Thread starter 17 years ago
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Thanks loads, I had factorised the last one but hadnt multiplied through properly. I understand it totally now.

Thanks again

Emma xxx
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