Ответ:

  1. \(\frac{5x-7-x+3+2x-8}{6x}=\frac{6x-12}{6x}=\frac{x-2}{x}\).
  2. \(\frac{8y-5-2y+1-10+y}{7y}=\frac{7y-14}{7y}=\frac{y-2}{y}\).
  3. \(\frac{x-5+12}{x^2-49}=\frac{x+7}{(x-7)(x+7)}=\frac{1}{x-7}\).
  4. \(\frac{y^2+2y-4y+4}{y^2-4y+4}=\frac{y^2-2y+4}{(y-2)^2}\).
  5. \(\frac{32-8+z}{z^2-2z}=\frac{z+24}{z(z-2)}\).

Ответ: а) \(\frac{x-2}{x}\); б) \(\frac{y-2}{y}\); в) \(\frac{1}{x-7}\); г) \(\frac{y^2-2y+4}{(y-2)^2}\); д) \(\frac{z+24}{z(z-2)}\).