Respuesta :

[tex](3x + 4)(6 {x}^{2} - 5x + 7) \\ = 18 {x}^{3} - 15 {x}^{2} + 21x + 24 {x}^{2} - 20x + 28 \\ = 18 {x}^{3} + 9 {x}^{2} + x + 28[/tex]

I hope I helped you^_^