If $A$ and $B$ are two matrices of order $4 \times m$ and $4 \times n$, respectively and $m=n$ then the order of matrix $(5 A-2 B)$ is :

$4 \times m$

The correct answer is Option 1: $4 \times m$

A is of order 4 × m

B is of order 4 × n

We are told m = n

So, both matrices A and B have the same order:  4 × m (or equivalently, 4 × n)

Now for the operation:

• 5A − 2B is valid only if A and B are of the same order — which they are: 4 × m

• Scalar multiplication does not change the order

Therefore, the order of (5A − 2B) is : 4 × m