Вопрос:

1. Выполните действия: 1) \(\frac{56x^3y^4}{z^5}\cdot\left(-\frac{z^4}{16x^2y^6}\right)\); 2) \(\frac{72a^7}{c^{10}}:(24a^3c^8)\); 3) \(\frac{8b-3c}{c}\cdot\frac{4c^2}{b^2-c^2}\); 4) \(\frac{6x-30}{x+8}:\frac{x^2-25}{2x+16}\).

Ответ:

  1. \[\frac{56x^3y^4}{z^5}\cdot\left(-\frac{z^4}{16x^2y^6}\right)=-\frac{56x^3y^4z^4}{16x^2y^6z^5}=-\frac{7x}{2y^2z}.\]
  2. \[\frac{72a^7}{c^{10}}:(24a^3c^8)=\frac{72a^7}{c^{10}\cdot24a^3c^8}=\frac{3a^4}{c^{18}}.\]
  3. \[\frac{8b-3c}{c}\cdot\frac{4c^2}{b^2-c^2}=\frac{4c(8b-3c)}{(b-c)(b+c)}.\]
  4. \[\frac{6x-30}{x+8}:\frac{x^2-25}{2x+16}=\frac{6(x-5)}{x+8}\cdot\frac{2(x+8)}{(x-5)(x+5)}=\frac{12}{x+5}.\]

Ответ: 1) \(-\frac{7x}{2y^2z}\); 2) \(\frac{3a^4}{c^{18}}\); 3) \(\frac{4c(8b-3c)}{(b-c)(b+c)}\); 4) \(\frac{12}{x+5}\).