27x^5-45x^4/9x^2

To simplify the expression (27x^5 - 45x^4) / 9x^2, first divide each term in the numerator by the denominator:

(27x^5 / 9x^2) - (45x^4 / 9x^2)

Next, simplfy each term:

(3x^3) - (5x^2)

Therefore, the simplified expression is 3x^3 - 5x^2.