Ответ:

  1. \(\frac{15ac^8}{18a^5c^2}=\frac{5c^6}{6a^4}\).
  2. \(\frac{36-6x}{36-x^2}=\frac{6(6-x)}{(6-x)(6+x)}=\frac6{x+6}\).
  3. \(\frac{x^2+8x+16}{4x+16}=\frac{(x+4)^2}{4(x+4)}=\frac{x+4}{4}\).
  4. \(\frac{y^6+y^4}{y^6+y^8}=\frac{y^4(y^2+1)}{y^6(y^2+1)}=\frac1{y^2}\).
  5. \(\frac{8y-12y^2}{3y-2}=\frac{4y(2-3y)}{-(2-3y)}=-4y\).
  6. \(\frac{a^2-25}{25-10a+a^2}=\frac{(a-5)(a+5)}{(a-5)^2}=\frac{a+5}{a-5}\).
  7. \(\frac{x^3+27}{x^3+3x^2-2x-6}=\frac{(x+3)(x^2-3x+9)}{(x+3)(x^2-2)}=\frac{x^2-3x+9}{x^2-2}\).

Ответ: 1) \(\frac{5c^6}{6a^4}\); 2) \(\frac6{x+6}\); 3) \(\frac{x+4}{4}\); 4) \(\frac1{y^2}\); 5) \(-4y\); 6) \(\frac{a+5}{a-5}\); 7) \(\frac{x^2-3x+9}{x^2-2}\).