Question 44141
You need to factorise:
{{{(4r2 - 25s2) / (2r2 + 3rs - 20s2)}}}
{{{((2r + 5s)(2r-5s)) / (2r2 + 3rs - 20s2)}}}
{{{((2r + 5s)(2r-5s)) / (((2r + 3s)( r+s))-21s^2)}}}
I hope this helps 
P.S. I am trying to start up my own homework help website. I would be extremely grateful if you would e-mail me some feedback on the help you received to adam.chapman@student.manchester.ac.uk