Ответ:\(\frac{14a}{b^{-3}}\cdot\frac{b^{-2}}{56a^4}=\frac{14}{56}a^{1-4}b^{3-2}=\frac{b}{4a^3}\).\(\frac{18x^{-6}}{y^5}\cdot\frac{7y^{-5}}{6x^{-12}}=\frac{18\cdot7}{6}x^{-6-(-12)}y^{-5-5}=21x^6y^{-10}=\frac{21x^6}{y^{10}}\).