17) 5/7(y - 7) – 3/7(14 - y) =

17) $$ \frac{5}{7}(y - 7) – \frac{3}{7}(14 - y) = \frac{5}{7}y - \frac{35}{7} - \frac{42}{7} + \frac{3}{7}y = \frac{8}{7}y - \frac{77}{7} = \frac{8}{7}y - 11$$

Ответ:$$\frac{8}{7}y - 11$$