You can put this solution on YOUR website! n^2-n-20/2n^2 x n^2 + 5n/n^2 - 25
=[(n^2-n-20)/(2n^2)]X[(n^2 + 5n)/(n^2 - 25)]
=[(n-5)(n+4)/(2n^2)]X[n(n + 5)/(n+5)(n-5)]
Factorisation in the nr of the first fraction.
And using formula a^2-b^2 = (a+b)(a-b) and here a = n and b =5
in the dr of the second fraction
=[n(n-5)(n+4)(n+5)]/[(2n^2)(n+5)(n-5)]
=[(n+4)/(2n)] ( canceling (n-5), (n+5) and n)