Решение:
$$\frac{9}{7}y + \frac{11}{12} = \frac{13}{18}$$
$$\frac{9}{7}y = \frac{13}{18} - \frac{11}{12}$$
$$\frac{9}{7}y = \frac{26}{36} - \frac{33}{36}$$
$$\frac{9}{7}y = -\frac{7}{36}$$
$$y = -\frac{7}{36} \cdot \frac{7}{9}$$
$$y = -\frac{49}{324}$$
Ответ: y = -49/324