express the product of (2/3x^2-1/2x) and (12x+4/5) as a trinomial

(2/3x^2-1/2x)(12x+4/5)

= 8x^3 + 8x^2 /15 - 6x^2 - 2x/5
= 8x^3 -82x^2 /15 - 2x/5