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What three elimination matrices e21 e31 e32 put a into its upper triangular form

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To transform matrix A into its upper triangular form using elimination matrices
\(e_(21)\), \(e_(31)\), and
\(e_(32)\), we perform a sequence of row operations.

1.
\(e_(21)\) eliminates the second row's first element:


\[e_(21) \cdot A = \begin{bmatrix} 1 & 0 & 0 \\ -a_(21)/a_(11) & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix} \cdot A\]

2.
\(e_(31)\) eliminates the third row's first element:


\[e_(31) \cdot e_(21) \cdot A = \begin{bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ -a_(31)/a_(11) & 0 & 1 \end{bmatrix} \cdot e_(21) \cdot A\]

3.
\(e_(32)\) eliminates the third row's second element:


\[e_(32) \cdot e_(31) \cdot e_(21) \cdot A = \begin{bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & -a_(32)/(a_(22) - a_(21)a_(12)/a_(11)) & 1 \end{bmatrix} \cdot e_(31) \cdot e_(21) \cdot A\]

After applying these elimination matrices in sequence, matrix \(A\) is transformed into its upper triangular form.

The complete question is probably:
How can the elimination matrices \(e_{21}\), \(e_{31}\), and \(e_{32}\) be utilized to transform matrix \(A\) into its upper triangular form? Provide a detailed explanation of the process and the specific operations performed by each elimination matrix.

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