we have the expression
[tex]\mleft(5x^3+2x-10\mright)+5x^2-4x+6+2x^3-3x^2+2[/tex]Group similar terms
[tex](5x^3+2x^3)+(5x^2-3x^2)+(2x-4x)+(10+6^{}+2)[/tex]Combine like terms
[tex]\begin{gathered} \mleft(8x^3\mright)+\mleft(2x^2\mright)+\mleft(-2x\mright)+\mleft(18\mright) \\ 8x^3+2x^2-2x+18 \end{gathered}[/tex]