2) 280 : (4a2c); c3

2) $$\frac{28a}{c^3} : (4a^2c) = \frac{28a}{c^3} \cdot \frac{1}{4a^2c} = \frac{28a}{4a^2c^4} = \frac{7}{ac^4}$$

Ответ: $$\frac{7}{ac^4}$$