Ответ:

  1. \(3x(4x^2-x)=12x^3-3x^2\).

  2. \(-5a^2(a^2-6a-3)=-5a^4+30a^3+15a^2\).

  3. \((8b^2-10b+2)\cdot0.5b=4b^3-5b^2+b\).

  4. \(x^3(x^5-x^2+7x-1)=x^8-x^5+7x^4-x^3\).

  5. \(-2c^2d^4(4c^2-c^3d+5d^4)=-8c^4d^4+2c^5d^5-10c^2d^8\).

Ответ: 1) \(12x^3-3x^2\); 2) \(-5a^4+30a^3+15a^2\); 3) \(4b^3-5b^2+b\); 4) \(x^8-x^5+7x^4-x^3\); 5) \(-8c^4d^4+2c^5d^5-10c^2d^8\).