Respuesta :

[tex] - 5x + 2y = 9 \\ y = 7x \\ \\ - 5x + 2 \times 7x = 9 \\ - 5x + 14x = 9 \\ 9x = 9 \\ x = 1 \\ \\ y = 7 \times 1 = 7 \\ [/tex]

Answer: (1; 7)