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Practice: Performing Independent Matrix Row Operations

When familiarizing oneself with matrix manipulation, it is useful to practice performing row operations independently on a single augmented matrix. For example, consider the matrix:

ight] $$ We can perform the following distinct operations, each applied separately to the original matrix: 1. Interchange rows $$1$$ and $$2$$: $$ \left[ \begin{array}{ccc|c} 4 & 1 & -3 & 2 \\ 2 & -3 & -2 & -4 \\ 5 & 0 & 4 & -1 \end{array} ight] $$ 2. Multiply row $$1$$ by $$2$$ (denoted $$2R_1$$): $$ \left[ \begin{array}{ccc|c} 4 & -6 & -4 & -8 \\ 4 & 1 & -3 & 2 \\ 5 & 0 & 4 & -1 \end{array} ight] $$ 3. Multiply row $$2$$ by $$3$$ and add to row $$1$$ (denoted $$3R_2 + R_1$$): First, multiply row $$2$$ by $$3$$ to get $$[12, 3, -9 \mid 6]$$. Adding this to row $$1$$ ($$[2, -3, -2 \mid -4]$$) yields a new row $$1$$ of $$[14, 0, -11 \mid 2]$$ and successfully eliminates the second variable: $$ \left[ \begin{array}{ccc|c} 14 & 0 & -11 & 2 \\ 4 & 1 & -3 & 2 \\ 5 & 0 & 4 & -1 \end{array} ight] $$

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Updated 2026-05-25

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