book Maths Puzzle Numerical Ability

Define the subgroups of the Real number system giving examples using set notation

Read Solution (Total 0)

book Other Question

All that I have to do is factor this but I think that it is prime. Can someone please tell me if I am right? Thank you.
15x^2+16x+4
(x+2/x-2) / (x^2-4/2x-4)

I don't even know where to begin on this. Could you help?