Выбери верные ответы

Выполни умножение.

1. \(\dfrac{x^4y}{28a}\cdot \Big(-\dfrac{7a}{x^3y^6}\Big)=\)
   [ \(-\frac {x}{4y^5}\) | \(\frac {7xy}{28}\) | \(-4xy\) | \(\frac {xy}{7}\) ].
2. \(16b^5\cdot \dfrac{7c^2}{8b^{10}}=\)
   [ \(\frac {7c^2}{b^5}\) | \(\frac {14c^2}{b^5}\) | \(14b^5c^2\) | \(\frac {9c^2}{b^5}\) ].
3. \(\dfrac{a^{n+2}b^{4n+3}}{c^{n+1}}\cdot \dfrac{c^{2n+1}}{a^nb^{4n}}=\)
   [ \(a^2b^3c^n\) | \(a^2b^3c^{n+2}\) | \(a^2b^3c^3\) | \(\frac {a^{2n+2}b^{8n+3}}{c}\) ].