Use Gaussian elimination with back substitution?

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Discussion Overview

The discussion revolves around the application of Gaussian elimination with back substitution to solve a specific system of linear equations. Participants explore the formatting of matrices and the setup of the augmented matrix in this context.

Discussion Character

  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant presents a system of equations and seeks clarification on the appropriate notation for matrices, specifically whether to use brackets or parentheses.
  • Another participant suggests that sharing a scanned image of the work could facilitate better understanding and assistance.
  • A third participant explains that the choice between using parentheses or brackets for matrices is largely a matter of convention, noting that both forms are acceptable as long as the augmented matrix is properly set up with a visual separator for the constants.
  • This participant emphasizes the importance of including a solid or dashed vertical line in the augmented matrix to distinguish between coefficients and constants.

Areas of Agreement / Disagreement

Participants generally agree on the conventions for matrix notation but do not reach a consensus on the specific formatting preferences. The discussion remains focused on clarifying these conventions rather than resolving the original problem.

Contextual Notes

There is an implicit assumption that participants are familiar with Gaussian elimination and matrix notation, but specific steps for solving the system are not provided.

Who May Find This Useful

Students learning about Gaussian elimination, educators discussing matrix notation, and individuals seeking clarification on formatting in mathematical contexts may find this discussion useful.

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Use Gaussian elimination with back substitution to solve the following system:

x1+x2+x3=1,
x1+2x2+2x3=1,
x1+2x2+3x3=1.

The answer is (1, 0, 0) and I know how to solve the problem but I just don't know if I should use bracket or the big parentheses for this type of problem when I solve this problem. Can anyone please provide me the work for this problem? Like do I use equal sign between the two bracket matrixes?
 
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I think if you show us a scanned image of your work, we can better understand/help you. Brackets are usually used to denote determinants, parentheses are used for matrices.
 
If you are to use Gaussian elimination you set up the augmented matrix. Whether you write the matrix as
<br /> \begin{pmatrix} 1 &amp; 1 &amp; 1 &amp; 1 \\ 1 &amp; 2 &amp; 2 &amp; 1 \\ 1 &amp; 2 &amp; 3 &amp; 1 \end{pmatrix}<br />

or
<br /> \begin{bmatrix} 1 &amp; 1 &amp; 1 &amp; 1 \\ 1 &amp; 2 &amp; 2 &amp; 1 \\ 1 &amp; 2 &amp; 3 &amp; 1 \end{bmatrix}<br />

is immaterial: some books use the first version, some the second. The thing in common is that (when you write by hand or see them in texts) there is typically a solid or dashed vertical line immediately before the final column (the line goes where the equal signs would be). That is used as a visual reminder that the numbers to the left are coefficients of equations while those to the right are the constants from the equations' right sides. Once you have the matrix set up you do the Guassian elimination work (which you need to do).
 
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Thank you, guys. I appreciated.
 

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