Ответ:

  1. \((8x-y^2)(3x+y^2)=24x^2+5xy^2-y^4\).
  2. \((2m^2n-5mn^2)(3mn^2-4m^2n)=-8m^4n^2+23m^3n^3-15m^2n^4\).
  3. \((5xy^2-2x^2y)(2x^2y+5xy^2)=25x^2y^4-4x^4y^2\).
  4. \(\left(\frac12a^3+b^2\right)\left(b^2-\frac12a^3\right)=b^4-\frac14a^6\).
  5. \((a^6-a^3b^3+b^6)(a^3+b^3)=a^9+b^9\).
  6. \((9m^4+3m^2n^2+n^4)(3m^2-n^2)=27m^6- n^6\).

Ответ: 1) \(24x^2+5xy^2-y^4\); 2) \(-8m^4n^2+23m^3n^3-15m^2n^4\); 3) \(25x^2y^4-4x^4y^2\); 4) \(b^4-\frac14a^6\); 5) \(a^9+b^9\); 6) \(27m^6-n^6\).