(7) Let M2x2(]R) be the set of all real 2 x 2 matrices: nggm): {A= (f: 3) |a,b,c,dE]R} Consider the following operation a: on G = MEXQUR): A*B=A+B+AB (a) Show that the Operation 3: is associative; (b) Show that (G, 4:) contains an identity element; (c) Is (G, a) a group? Hint: Observe that A at B = (I + A)(I + B) I where I is the identity matrix. Try to nd an inverse with respect to a for some specic matrix A satisfying det(A + I) = 0