Verified answer

Ответ: 3й

[tex]\left \{ {{5x - 2y = - 4 \: \: | \times 2} \atop {3x + 4y = - 18 \: \: \: \: \: \: }} \right. \\ \\ \left \{ {{10x - 4y = - 8} \atop {3x + 4y = - 18}} \right. + \\ 13x = - 26[/tex]