ж) 4/7 * (-49); з) -16: (-4/9); и) -3 1/2 * (-1 1/7).

<h1>Решение</h1> <ol> <li>$$\frac{4}{7} \cdot (-49) = -(\frac{4}{7} \cdot 49) = -(\frac{4 \cdot 49}{7}) = -(\frac{4 \cdot 7 \cdot 7}{7}) = - (4 \cdot 7) = -28$$ </li> <li>$$-16 : (-\frac{4}{9}) = 16 : \frac{4}{9} = 16 \cdot \frac{9}{4} = \frac{16 \cdot 9}{4} = \frac{4 \cdot 4 \cdot 9}{4} = 4 \cdot 9 = 36$$ </li> <li>$$-3 \frac{1}{2} \cdot (-1 \frac{1}{7}) = 3 \frac{1}{2} \cdot 1 \frac{1}{7} = \frac{3 \cdot 2 + 1}{2} \cdot \frac{1 \cdot 7 + 1}{7} = \frac{7}{2} \cdot \frac{8}{7} = \frac{7 \cdot 8}{2 \cdot 7} = \frac{8}{2} = 4$$ </li> </ol>