B. [tex]6 {x}^{3} + 5 {x}^{2} - 9x + 18[/tex] ✅
[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]
[tex](6 {x}^{3} + 3 {x}^{2} + 8) + (2 {x}^{2} - 9x + 10) \\ = 6 {x}^{3} + 3 {x}^{2} + 2 {x}^{2} - 9x + 8 + 10 \\ = 6 {x}^{3} + 5 {x}^{2} - 9x + 18[/tex]
[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{!}}}}}[/tex]
