Ответ:

  1. \(\frac{(4c-d)\cdot2(c-d)(c+d)}{c(c+d)\cdot c(4c-d)}=\frac{2(c-d)}{c^2}\).
  2. \(\frac{(b-3)^2}{b^2-3b+9}\cdot\frac{(b+3)(b^2-3b+9)}{5(b-3)}=\frac{b^2-9}{5}\).
  3. \(\frac{a(a-4)(a+4)}{3a^2b}\cdot\frac{3ab^2}{a+4}=b(a-4)\).
  4. \(\frac{(a+b)(a^2-ab+b^2)}{(a-b)(a+b)}\cdot\frac{7(a-b)}{a^2-ab+b^2}=7\).
  5. \(\frac{m+2n}{2-3m}\cdot\frac{m(3m-2)}{(m+2n)^2}=-\frac{m}{m+2n}\).
  6. \(\frac{(a+2)(a^2-2a+4)}{(4-a^2)(a^2+4)}\cdot\frac{a^2+4}{a^2-2a+4}=\frac1{2-a}\).
  7. \(\frac{(x-6)^2}{3(x+7)}\cdot\frac{4(x-6)}{(x-7)(x+7)}=\frac{4(x-6)^3}{3(x-7)(x+7)^2}\).
  8. \(\frac{3(a+5b)}{(a-9b)(a+9b)}\cdot\frac{(a-9b)^2}{4(a+5b)}=\frac{3(a-9b)}{4(a+9b)}\).

Ответ: 1) \(\frac{2(c-d)}{c^2}\); 2) \(\frac{b^2-9}{5}\); 3) \(b(a-4)\); 4) \(7\); 5) \(-\frac{m}{m+2n}\); 6) \(\frac1{2-a}\); 7) \(\frac{4(x-6)^3}{3(x-7)(x+7)^2}\); 8) \(\frac{3(a-9b)}{4(a+9b)}\).