## Elementary Technical Mathematics

$$-6x^3+36x^5-54x^7.$$
By multiplying each term of the polynomial by the monomial, and then adding the products, we have $$-6x^3(1-6x^2+9x^4)=-6x^3(1)-6x^3(-6x^2)-6x^3(9x^4)\\ =-6x^3+36x^5-54x^7.$$