3. Упростите: 1) (14a/b⁻³) · (b⁻²/(56a⁴)); 2) (18x⁻⁶/y⁵) · (7y⁻⁵/(6x⁻¹²)).

1. \[\frac{14a}{b^{-3}}\cdot\frac{b^{-2}}{56a^4}=\frac{14ab^3b^{-2}}{56a^4}=\frac{1}{4}\cdot\frac{b}{a^3}=\frac{b}{4a^3}.\]
2. \[\frac{18x^{-6}}{y^5}\cdot\frac{7y^{-5}}{6x^{-12}}=21x^{-6+12}y^{-5-5}=21x^6y^{-10}=\frac{21x^6}{y^{10}}.\]

Ответ: 1) \(\frac{b}{4a^3}\); 2) \(\frac{21x^6}{y^{10}}\).