2x^4-3x^3-11x^2+3x+9
=2×(2/3)^4-3×(2/3)^3-11×(2/3)^2+3×2/3+9
=2×16/81-3×8/27-11×4/9+2+9
=32/81-8/9-44/9+11
=455/81