SOLUTION: Morning, I am looking at a couple of questions on an problem sheet, on partial fractions. Express the following in partial fractions a) x+4/(2x+5)(x+2) b) 1/(x+1)(x^

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Morning, I am looking at a couple of questions on an problem sheet, on partial fractions. Express the following in partial fractions a) x+4/(2x+5)(x+2) b) 1/(x+1)(x^      Log On


   

Question 357825: Morning,
I am looking at a couple of questions on an problem sheet, on partial fractions.
Express the following in partial fractions
a) x+4/(2x+5)(x+2)
b) 1/(x+1)(x^2-1)
Ok so i have had a look at both questions, part a i think i may have conquered, i got an answer of
x+4/(2x+5)(x+2)= (1.5/-0.5(2x+5)) + (2/(x+2))
But the part b, i dont know where to go with?
Any responces would be greatly recieved.
Thanks
Mike
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Part a is correct but why not -3 instead of %281.5%2F%28-0.5%29%29??
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.
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Part b denominator can be factored to %28x%2B1%29%28x%5E2-1%29=%28x%2B1%29%28x-1%29%28x%2B1%29=%28x-1%29%28x%2B1%29%5E2
So look for a partial fraction expansion of,
+1%2F%28%28x%2B1%29%28x%5E2-1%29%29+=A%2F%28x-1%29%2BB%2F%28x%2B1%29%2BC%2F%28x%2B1%29%5E2