A good answer might be:

( 8, 4, 6 )T  + ( 2, -2, 9 )T = ( 10, 2, 15 )T

( 2, -2, 9 )T + ( 8,  4, 6 )T = ( 10, 2, 15 )T

Commutative

Matrix addition is commutative. This means that

a + b = b + a.

This works for both row and column matrices of all dimensions. It is also true that:

a + b + c = b + c + a = c + a + b = .....

In other words, the order in which you add matrices does not matter. At least for addition, matrices work the same way as numbers, since, of course, 1 + 2 = 2 + 1.

Matrices and numbers usually do NOT work the same way! But they do for addition.

QUESTION 5:

Contemplate this problem:

( -1, -2, 3 )T  + ( 1, 2, -3 )T =