Ответ:

  1. \((4x+3)^2-24x=16x^2+24x+9-24x=16x^2+9\).
  2. \(18c^2-2(c-1)^2=18c^2-2(c^2-2c+1)=16c^2+4c-2\).
  3. \((2x-5)^2+20x=4x^2-20x+25+20x=4x^2+25\).
  4. \(36c-3(1+6c)^2=36c-3(1+12c+36c^2)=36c-3-36c-108c^2=-108c^2-3\).