Ответ: (2; -1)

Объяснение:

[tex]\left \{ {{5x+3y = 7} \atop {-2x+4y=-8}} \right.[/tex]

[tex]\left \{ {{10x+6y=14} \atop {-10x+20y=-40}} \right.[/tex]

[tex]\left \{ {{10x+6y=14} \atop {26y=-26}} \right.[/tex]

[tex]\left \{ {{x=\frac{14-6y}{10} } \atop {y=-1}} \right.[/tex]

[tex]\left \{ {{x=2} \atop {y=-1}} \right.[/tex]