Ответ:

Вариант Б1

  1. \(\frac{15x^4-25x^3}{5x^5}=\frac{5x^3(3x-5)}{5x^5}=\frac{3x-5}{x^2}\).
  2. \(\frac{9y^2-1}{9y-3}=\frac{(3y-1)(3y+1)}{3(3y-1)}=\frac{3y+1}{3}\).
  3. \(\frac{a^2+4a+4}{4-a^2}=\frac{(a+2)^2}{(2-a)(2+a)}=\frac{a+2}{2-a}\).

Вариант Б2

  1. \(\frac{6x^2+18x^4}{12x^3}=\frac{6x^2(1+3x^2)}{12x^3}=\frac{1+3x^2}{2x}\).
  2. \(\frac{25y^2-4}{25y+10}=\frac{(5y-2)(5y+2)}{5(5y+2)}=\frac{5y-2}{5}\).
  3. \(\frac{9-a^2}{a^2+6a+9}=\frac{(3-a)(3+a)}{(a+3)^2}=\frac{3-a}{a+3}\).