To multiply a binomial and a trinomial, order the terms by descending exponent, multiply the coefficients and add the exponents of like terms, then combine the terms in descending exponent order. Specifically, (5x^6 + 9x^3 + 3x)(8x^5 + 3x^4) = 40x^11 + 15x^10 + 72x^8 + 27x^7 + 24x^6 + 9x^5.