The problem is: Let K = a 2x2matrix where a is a real number and does not equal zero. That is, all 2x2 in which each entry is the same. Show that is a group under multiplication. And find its identity element. Verify. Please note: That the basic idenity matrix is not the identity element I have been looking through even book I own, but if all the entries are the same, couldn't that make the matrix singular?