Calculate the determinant .
Solution: Use the properties of the determinant . It is noted that the sum of numbers in each row (column) of the determinant is , so the , , rows are added to the row at the same time , and the common factor is proposed , and then each row is subtracted from the 4th. line is converted into an upper triangle determinant to calculate.
Note: More general results can be obtained by following the above method:
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