PLEASE HELP ME

In the first part of the question the filled in box for BC is incorrect!

B = [-4, 2

        0, 5]

C = [0, 4, -1

        1, 0, 4]

B*C = [-4*0+2*1, -4*4+2*0,  -4*(-1)+2*4

           0*0+5*1,  0*4+5*0,    0*(-1)+5*4]

B*C = [2, -16, 12

           5,  0,   20]

For the second part, A - B means subtract corresponding elements in A and B.