Answer:
false
Step-by-step explanation:
[tex]\left[\begin{array}{c}-4\end{array}\right] +\left[\begin{array}{c}7\end{array}\right] =\left[\begin{array}{c}3\end{array}\right][/tex]
Both of the matrices are 1 x 1 ("one by one"), so they can be added to produce a 1 x 1 matrix.
To add (or subtract) two matrices, they must be the same size.
(m x n) + (m x n) = (m x n)
m x n means a matrix has m rows and n columns. Dimensions are always named in that order: rows, then columns.
