Im unsure how you would multpy the second one since it doesnt have the same dimensions and for the first question i am completely confused.
2)
B = 2 x 2 C = 2 x 3
So
B * C = [ 2 x 2 ] * [ 2 x 3 ] the "inner" dimensions are the same so the result will be the "outer" dimensions =
2 x 3 = 2 rows and 3 columns
So we have
[ -4 2 ] x [ 0 4 -1 ] = [ (-4 * 0 + 2 * 3) ( -4*4 + 2*0) ( -4*-1 + 2*1) ] =
[ 0 5 ] [ 3 0 1 ] [ ( 0*0 + 5*3 ) (0*4 + 5*0) ( 0*-1 + 5* 1) ]
[ 6 - 16 6 ]
[ 15 0 5 ]