17) 5\frac{1}{7}(y - 7)-3\frac{3}{7}(14- y) =

17) $$5\frac{1}{7}(y - 7)-3\frac{3}{7}(14- y) = \frac{36}{7}(y-7) - \frac{24}{7}(14-y) = \frac{36}{7}y - \frac{36}{7} \cdot 7 - \frac{24}{7} \cdot 14 + \frac{24}{7}y = \frac{36}{7}y - 36 - 24 \cdot 2 + \frac{24}{7}y = \frac{36}{7}y + \frac{24}{7}y - 36 - 48 = \frac{60}{7}y - 84$$

Ответ: $$\frac{60}{7}y - 84$$