I figured out the quiz question for material prices by substitution, but can’t figure out how to perform row reducing… I have been trying various manipulations such as dividing the first row by the coefficient of the first column (variable?)… but then it all gets messy (fractions) and still I can’t seem to isolate to one variable anywhere… any hints/suggestions? I reviewed the row reduction section but can’t find anything useful. Thanks for any help!
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I also had troubles with this - would love to see a walkthrough of row reduction for this problem
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Thanks for responding gdelgado. I just figured it out… Basically you start by moving the row that starts with a 1 to the top, then work on making the first column zero for each subsequent row. After that, you attack the second column. The idea is to get all zeros below the main diagonal, and you can have anything above it. It took some persistence but I did get it! I know we aren’t supposed to post specific answers here, but let me know if that helps you?
here’s an algorithm I came up with for row reduction:
1) Fix the first row at one in the first column
2) Fix subsequent rows to zero in the first column
3) Use these rows to fix the second column, second row to 1
4) Then fix the rows below to zero in that column
5) Repeat for additional columns to the right
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A key piece of the puzzle would be to use fractions instead of decimals. I think using decimals in the process kind of complicated things for me.