1. Выполните деление: 1) -42 : 6; 2) -80,96 : (-16); 3) \(\frac{42}{55} : \left(-\frac{35}{99}\right)\); 4) \(-1\frac{21}{45} : 4\frac{8}{9}\).

Решение:

1. \( -42 : 6 = -7 \)
2. \( -80,96 : (-16) = 5,06 \)
3. \(\frac{42}{55} : \left(-\frac{35}{99}\right) = \frac{42}{55} \times \left(-\frac{99}{35}\right) = \frac{42 \times (-99)}{55 \times 35} = \frac{(6 \times 7) \times (-9 \times 11)}{(5 \times 11) \times (5 \times 7)} = \frac{6 \times (-9)}{5 \times 5} = -\frac{54}{25} = -2\frac{4}{25}\)
4. \(-1\frac{21}{45} : 4\frac{8}{9} = -\frac{66}{45} : \frac{44}{9} = -\frac{66}{45} \times \frac{9}{44} = -\frac{66 \times 9}{45 \times 44} = -\frac{(6 \times 11) \times 9}{(5 \times 9) \times (4 \times 11)} = -\frac{6}{5 \times 4} = -\frac{6}{20} = -\frac{3}{10}\)

Ответ: 1) -7; 2) 5,06; 3) \(-2\frac{4}{25}\); 4) \(-\frac{3}{10}\).