Example

Solving \left\{\begin{array}{l} 4x - 3z = -5 \\ 3y + 2z = 7 \\ 3x + 4y = 6 \end{array} ight. by Elimination

To solve the linear system \left\{\begin{array}{l} 4x - 3z = -5 \\ 3y + 2z = 7 \\ 3x + 4y = 6 \end{array} ight. using the elimination method, systematically pair equations to reduce the problem's dimensionality. Eliminate zz from the first two equations by multiplying the first by 22 (yielding 8x6z=108x - 6z = -10) and the second by 33 (yielding 9y+6z=219y + 6z = 21). Integrating these formulas cancels zz to reliably state a new equation: 8x+9y=118x + 9y = 11.

Bringing this calculated statement together with the unused third equation outlines a localized two-variable system: \left\{\begin{array}{l} 8x + 9y = 11 \\ 3x + 4y = 6 \end{array} ight.. Next, choose to eliminate yy by multiplying the first equation by 44 to obtain 32x+36y=4432x + 36y = 44 and the second by 9-9 to create 27x36y=54-27x - 36y = -54. Adjoining these equations strictly isolates 5x=105x = -10, simplifying cleanly to x=2x = -2. Substituting x=2x = -2 directly back into the third original equation allows deduction of the localized variable yy as 33. Furthermore, placing y=3y = 3 into the second equation predictably reveals z=1z = -1. When written compactly, the functional solution successfully manifests as the tested ordered triple (2,3,1)(-2, 3, -1).

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Updated 2026-04-25

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