Вопрос:

1. Выполните действия: 1) \(\frac{54a^8b^8}{c^{12}}\cdot\left(-\frac{c^{20}}{12a^4b^{16}}\right)\); 2) \(\frac{98m^8}{p^{17}}:(49mm^5p^2)\); 3) \(\frac{5a+5b}{b}\cdot\frac{6b^2}{a^2-b^2}\); 4) \(\frac{x^2-49}{3x-24} : \frac{5x+35}{x-8}\).

Ответ:

  1. \[\frac{54a^8b^8}{c^{12}}\cdot\left(-\frac{c^{20}}{12a^4b^{16}}\right)=-\frac{54}{12}a^{8-4}b^{8-16}c^{20-12}=-\frac{9a^4c^8}{2b^8}.\]
  2. \[\frac{98m^8}{p^{17}}:(49m^6p^2)=\frac{98m^8}{p^{17}}\\times\frac{1}{49m^6p^2}=\frac{2m^2}{p^{19}}.\]
  3. Разложим на множители: \(5a+5b=5(a+b)\), \(a^2-b^2=(a-b)(a+b)\).
    \[\frac{5(a+b)}{b}\cdot\frac{6b^2}{(a-b)(a+b)}=\frac{30b}{a-b}.\]
  4. Разложим на множители: \(x^2-49=(x-7)(x+7)\), \(3x-24=3(x-8)\), \(5x+35=5(x+7)\).
    \[\frac{(x-7)(x+7)}{3(x-8)}:\frac{5(x+7)}{x-8}=\frac{(x-7)(x+7)}{3(x-8)}\cdot\frac{x-8}{5(x+7)}=\frac{x-7}{15}.\]

Ответ: 1) \(-\frac{9a^4c^8}{2b^8}\); 2) \(\frac{2m^2}{p^{19}}\); 3) \(\frac{30b}{a-b}\); 4) \(\frac{x-7}{15}\).