Answer:
( -1, -2, 3 )T + ( 1, 2, -3 )T = ( 0, 0, 0 )T
( -1, -2, 3 )T + ( 1, 2, -3 )T = ( 0, 0, 0 )T
Here is a problem which will probably not be on the midterm:
( 73.6, -41.4 )T + ( 0.0, 0.0 )T = (73.6, -41.4 )T
A matrix with all zero elements is sometimes called a zero matrix. The sum of a zero matrix and a matrix a of the same type is just a.
In symbols the zero matrix is written as 0 (bold face zero) which is different than 0, the real number zero. The context in which you see 0 determines whether it is a row or a column and how many elements it has. So if you see
(73.6, -41.4 )T + 0
you can assume that 0 is the right type of matrix for the expression.
Do the following problem (which might be on the midterm):
( 2, 5, -9 ) + ( -32.034, 94.79, 201.062 ) + ( -2, -5, 9 ) =