Suppose that A = and B = , for some real numbers x and y. Find all ordered pairs (x,y) such that AB =BA. (Enter your answer as a list of ordered pairs; for example, (1,2), (3,4),(5,6). ) Solution x*x x*x x*x +xy 4x xy +4 xy +4y x + y*y 4y x=0 or y=0 , x=0,4 ............... , x=0 , y=0 x=0 , y= +- 2 answer.