Сократи дроби: 1) \(\frac{12a^8x^9}{4a^2x^{11}}\); 2) \(\frac{x-y}{x^2-y^2}\); 3) \(\frac{a^2-2ay+y^2}{a-y}\); 4) \(\frac{n^2-x^2}{n^2+2nx+x^2}\); 5) \(\frac{3c-12}{16-c^2}\).

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

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