Решение:
- a)\[ 0.3a(4a^2 - 3)(2a^2 + 5) = 0.3a(8a^4 + 20a^2 - 6a^2 - 15) = 0.3a(8a^4 + 14a^2 - 15) = 2.4a^5 + 4.2a^3 - 4.5a \]
- б)\[ 1.5x(3x^2 - 5)(2x^2 + 3) = 1.5x(6x^4 + 9x^2 - 10x^2 - 15) = 1.5x(6x^4 - x^2 - 15) = 9x^5 - 1.5x^3 - 22.5x \]
Ответ: a) $$2.4a^5 + 4.2a^3 - 4.5a$$; б) $$9x^5 - 1.5x^3 - 22.5x$$