Answer: D) 7
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Explanation:
a31 means "the value in the third row, first column". That value is 7
As another example, a22 = 3 since 3 is in the second row, second column.
Another example: a12 = -1 because we're in the first row and second column.
This is a 3x2 matrix due to it having 3 rows and 2 columns.
