[tex]\begin{cases} 5x + 4y = 6 \\ 2x + y = 3 | \cdot ( - 4)\end{cases}[/tex]
[tex]\begin{cases} 5x + 4y = 6 \\ - 8x - 4y = - 12\end{cases}[/tex]
[tex] 5x + ( - 8x) = 6 + ( - 12)[/tex]
[tex] - 3x = - 6 | \div ( - 3) \\ x = 2[/tex]
[tex]5 \times 2 + 4y = 6 \\ 10 + 4y = 6 \\ 4y = - 4 | \div 4 \\ y = - 1[/tex]
[tex] \large{\begin{cases} x = 2 \\ y = - 1\end{cases}}[/tex]
Sprawdzenie:
[tex]5x + 4y = 6 \\ 5 \times 2 + 4 \times ( - 1) = 6 \\ 10 + ( - 4) = 6 \\ L = P[/tex]
[tex]2x + y = 3 \\ 2 \times 2 + ( - 1) = 3 \\ 4 + ( - 1) = 3 \\ L = P[/tex]
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