# Math Help - Sum and Product of Matrices

1. ## Sum and Product of Matrices

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Two matrices may be multiplied provided the number of elements in the rows of A=number of elements in the columns of B. So, there is not a single pair that could be multiplied in this question? And what about A*2 and addition ?

2. Originally Posted by Tron
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Two matrices may be multiplied provided the number of elements in the rows of A=number of elements in the columns of B. So, there is not a single pair that could be multiplied in this question? And what about A*2 and addition ?

The products $BC\,,\,DB\,,\,CA\,,\,A^2\,,\,D^2$ exist .

And the most correct way to tell the condition for multiplication: we can multiply two

matrices iff the the left matrix's number of columns equals the right one's number of rows.

Tonio