I dont want the answer to this this but if someone could guide me in the right direction it would be much appreciated.

Consider the set M_n (R) of n x n matrices over R. For A,B \in M_n (R) say that B is similar to A if and only if there is an invertible matrix P with B = P^-1 A P. Show that similarity is an equivalence relation on M_n (R).

If i understand right to prove this i have to show that the set M_n (R) is refexive, symmetric and transitive but im not sure how to do this... Any help please!

Something weirds happened to my Latex stuff so im leaving it out, (R) means real numbers. \in is that symbol that looks like a mix between C and E.