Вопрос:

Задание 20. Сократи дроби: 1) 12a⁸x⁹/(4a²x¹¹); 2) (x−y)/(x²−y²); 3) (a²−2ay+y²)/(a−y); 4) (n²−x²)/(n²+2nx+x²); 5) (3c−12)/(16−c²).

Ответ:

  1. \(\frac{12a^8x^9}{4a^2x^{11}}=\frac{3a^6}{x^2}\).
  2. \(\frac{x-y}{x^2-y^2}=\frac{x-y}{(x-y)(x+y)}=\frac1{x+y}\).
  3. \(\frac{a^2-2ay+y^2}{a-y}=\frac{(a-y)^2}{a-y}=a-y\).
  4. \(\frac{n^2-x^2}{n^2+2nx+x^2}=\frac{(n-x)(n+x)}{(n+x)^2}=\frac{n-x}{n+x}\).
  5. \(\frac{3c-12}{16-c^2}=\frac{3(c-4)}{(4-c)(4+c)}=-\frac3{c+4}\).

Ответ: 1) \(\frac{3a^6}{x^2}\); 2) \(\frac1{x+y}\); 3) \(a-y\); 4) \(\frac{n-x}{n+x}\); 5) \(-\frac3{c+4}\).