jamesk486
Really wants to Beat The GMAT!
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 Posted: Thu May 10, 2007 11:53 pm Post subject: inequality question- could someone check my work pls? |
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x is not 1, (1-x^5)/(1-x) < 1/1-x
(1) x>0
(2) x<1
using (1-x^5)/(1-x) < 1/1-x
=> (1/1-x) - (x^5/1-x) < 1/1-x
=> -x^5/(1-x)<0
=> multiplying each side by (1-x)^2 since its positive
=> -x^5(1-x) which is also x^5*(x-1)<0
=> dividing each side by x^4, we get x(x-1)<0, so the answer must be c
but what if from -x^5/(1-x)<0, is it possible to mulitply each side by (-1) to get x^5/(1-x) >0?
for some reason if i do it that way my answer comes out differently..
(the answer is C btw) |
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