<PRE><B>Question 626978</B>
The first two rows of the following matrix are already in triangular form. Finish the job by performing Gaussian elimination on row 3. What are the contents of row 3 after you have done so? 
[1 6 -2 0]
[0 -3 1 5]
[2 0 3 9] 
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Subtract 2 times the 1st line from the 3rd line to get:
 
[1 6 -2 0]
[0 -3 1 5]
[0-12 7 9]
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Ans: [0 -12 7 9]
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Cheers,
Stan H.
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