Example

Solving {2x2y+3z=64x3y+2z=02x+3y7z=1\left\{\begin{array}{l} 2x - 2y + 3z = 6 \\ 4x - 3y + 2z = 0 \\ -2x + 3y - 7z = 1 \end{array}\right. by Elimination

To solve the system {2x2y+3z=64x3y+2z=02x+3y7z=1\left\{\begin{array}{l} 2x - 2y + 3z = 6 \\ 4x - 3y + 2z = 0 \\ -2x + 3y - 7z = 1 \end{array}\right. by elimination, first eliminate the variable xx. Adding the first and third equations together directly yields the two-variable equation y4z=7y - 4z = 7. Next, multiply the third equation by 22 and add it to the second equation to produce another two-variable equation, 3y12z=23y - 12z = 2. This forms a new sub-system of equations: {y4z=73y12z=2\left\{\begin{array}{l} y - 4z = 7 \\ 3y - 12z = 2 \end{array}\right.. To eliminate a variable from this sub-system, multiply the first equation by 3-3 and add it to the second equation. This completely removes the variables and results clearly in the false mathematical statement 0=190 = -19. Because we are left firmly with a false numerical statement, the system is inconsistent and yields no solution.

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Updated 2026-04-25

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