Inactive Tutor answered • 06/11/14
Tutor
New to Wyzant
First I would get rid of the parenthesis since multiplication and division aren't really the issues here so you can rewrite it like this first.
4/x+1 + 1/x^2 -x + 1 - 12 /x^3 - 1
4/x+1 + 1/x^2 -x + 1 - 12 /x^3 - 1
Then you can group thinks out.
-12/ x^3 + 1/ x^2 + 4/ x -x +1......and that's one form. I'll post another comment if I read the expression wrong.
Philip P.
tutor
If you factor the denominators, the expression becomes:
4 1 12
------ + ------------ - ---------------
(x+1) (x+1)(x-1) (x+1)2(x-1)
Put the terms over a common denominator, which will be (x+1)2(x-1). Then add and subtract the numerators and simplify.
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06/11/14
Steve G.
The second fraction you have is incorrect. if foiled that would give me x^2-1 not x^2-x+1
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06/11/14
Philip P.
tutor
You are right! It should be:
4 1 12
------- + ---------- - -----------------
(x+1) (x2-x+1) (x+1)(x2-x+1)
Common denominator is (x+1)(x2-x+1)
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06/11/14
Steve G.
Thank you! I am still having trouble with it though. The book is saying the answer is 4x-7. I keep getting 4x^2-15x-7
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06/12/14
Philip P.
tutor
When you put it over the common denominator, you get:
4x2-3x-7 (x+1)(4x-7) 4x-7
----------------- = ------------------ = ------------
(x+1)(x2-x+1) (x+1)(x2-x+1) (x2-x+1)
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06/12/14
Steve G.
06/11/14