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September 24th, 2012, 12:47 PM   #1
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Rational expression constants

Find, Algebraically, the constants A and B such that 7x-6 / x^2-x-6 = A/x+2 + B/x-3
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September 24th, 2012, 01:20 PM   #2
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Re: Rational expression constants

Will you post your attempt and/or any ideas you have?
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September 24th, 2012, 01:43 PM   #3
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Re: Rational expression constants

yea sure, here they are:

ive tried using (x+2)(x-3) as the denominator and took it out from all 3

then, ax + 3a + bx + 2b = 7x-6

ive tried substituting a and couldnt go any further than this
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September 24th, 2012, 01:47 PM   #4
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Re: Rational expression constants



Now set x = 3 and you get B = 3. Do you see how?
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September 24th, 2012, 02:11 PM   #5
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Re: Rational expression constants

I've tried following your suggestions but couldn't quite get the 3 for B, however what I got was 7x-6 = B by eliminating all the like factors and can you also elaborate on the rules of plugging in the 3 as x. Thanks
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September 24th, 2012, 02:14 PM   #6
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Re: Rational expression constants

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September 24th, 2012, 02:18 PM   #7
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Re: Rational expression constants

alright I see, I just made a small error and forgot to put 5 infront of B. Anyways, thanks for clearing this up.
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