| Matrix | 
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 An array of numbers is called a matrix.  | 
 
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Figure 1. | 
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Matrices can only be multiplied if the number of columns in the first matrix is equal to the number of the rows in the second matrix.
 
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Figure 2. | 
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Below, we are multiplying two 2 x 2 matrices:
 
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Figure 3. | 
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Now, we have our final result:
 
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Figure 4. | 
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