б) $$\frac{18}{25} - \frac{7}{25} + y = \frac{14}{25}$$
$$\frac{18-7}{25} + y = \frac{14}{25}$$
$$\frac{11}{25} + y = \frac{14}{25}$$
$$y = \frac{14}{25} - \frac{11}{25}$$
$$y = \frac{14-11}{25}$$
$$y = \frac{3}{25}$$
Ответ: $$\frac{3}{25}$$