Ответ:
- \(\frac{6x^2}{5y}:\frac{3x}{10y^3}=\frac{6x^2}{5y}\cdot\frac{10y^3}{3x}=4xy^2\).
- \(\frac{8c}{21d^2}:\frac{6c^2}{7d}=\frac{8c}{21d^2}\cdot\frac{7d}{6c^2}=\frac{4}{9cd}\).
- \(\frac{3ab}{4xy}:\left(-\frac{21a^2b}{10x^2y}\right)=\frac{3ab}{4xy}\cdot\left(-\frac{10x^2y}{21a^2b}\right)=-\frac{5x}{14a}\).
- \(-\frac{18a^2b^2}{5cd}:\left(-\frac{9ab^3}{5c^2d^4}\right)=\frac{18a^2b^2}{5cd}\cdot\frac{5c^2d^4}{9ab^3}=\frac{2acd^3}{b}\).
Ответ: а) \(4xy^2\); б) \(\frac{4}{9cd}\); в) \(-\frac{5x}{14a}\); г) \(\frac{2acd^3}{b}\).
