There is a polynomial which, when multiplied by x^2 + 2x + 3, gives 2x^5 + 3x^4 + 7x^3 + 6x^2 + 15x + 9. What is that polynomial? (Give your answer as a polynomial in which the terms appear in order of decreasing degree. In other words, "x^5 + x + 2" is a valid answer, but "2 + x^5 + x" is not.)
