Ответ:

  1. \((x-2)(x-11)-2x(4-3x)=x^2-13x+22-8x+6x^2=7x^2-21x+22\).
  2. \((a+6)(a-3)+(a-4)(a+5)=a^2+3a-18+a^2+a-20=2a^2+4a-38\).
  3. \((y-8)(2y-1)-(3y+1)(5y-2)=2y^2-17y+8-(15y^2-y-2)=-13y^2-16y+10\).
  4. \((x+2)^2-(x-3)(x+3)=x^2+4x+4-(x^2-9)=4x+13\).
  5. \((7a-5b)(7a+5b)-(4a+7b)^2=49a^2-25b^2-(16a^2+56ab+49b^2)=33a^2-56ab-74b^2\).
  6. \((y-2)(y+3)-(y-1)^2+(5-y)(y+5)=y^2+y-6-y^2+2y-1+25-y^2=-y^2+3y+18\).