Question 77293
(n^2-n-20/2n^2)*
[(n^2+5n)/(n^2-25)]
Factor where you can to get:
=[(n-5)(n+4)/2n^2]*
[n(n+5)/(n+5)(n-5)]
Cancel factors that are common to numerator and denominator to get:

=[(n+4)/2n]*[1/(n-5)]

=(n+4)/[2n(n-5)]

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Cheers,
Stan H.