Respuesta :
[tex] \frac{1}{2} {x}^{2} y + {x}^{3} {y}^{2} - 9 = \\ \frac{1}{2} \times {2}^{2} \times 3 + {2}^{3} \times {3}^{2} - 9 = \\ \frac{1}{2} \times 4 \times 3 + 8 \times 9 - 9 = \\ 2 \times 3 + 72 - 9 = \\ 6 + 72 - 9 = \\ 78 - 9 = \\ 69[/tex]