Ответ:

[tex]7x - 8 - 9x - 3 = \frac{15}{7} \times \frac{7}{15} \times x - \frac{15}{7} \times \frac{14}{10} [/tex]

[tex] - 2x - 12 = x - 3[/tex]

-3x = 9

x = - 3