The Manhattan GMAT Guide 2(Algebra) on p. 156 has a rational function with absolute value, f(1/x) =
|(x+1)/(1-x)| and then it is simplified as follows: |(x+1)/-(1-x)|, here is my question: how did the writer move from the first form to the 2nd one?
If he/she had taken out a negative as a common factor then the expression would be |(x+1)/-(-1+x)| but then the negative sign disappeared later one to yield the following: |(x+1)/(x-1)|
Is it possible that the writer multiplied by -1? but then it would have to be multiplied by the top and bottom parts..right?
Any help would be appreciated..thank you.
|(x+1)/(1-x)| and then it is simplified as follows: |(x+1)/-(1-x)|, here is my question: how did the writer move from the first form to the 2nd one?
If he/she had taken out a negative as a common factor then the expression would be |(x+1)/-(-1+x)| but then the negative sign disappeared later one to yield the following: |(x+1)/(x-1)|
Is it possible that the writer multiplied by -1? but then it would have to be multiplied by the top and bottom parts..right?
Any help would be appreciated..thank you.
