[tex](2x+4)(2x^2-3x+2)[/tex]
We must add the result of the multiplication of each term of the first parenthesis with the second parenthesis
[tex]\begin{gathered} (2x\times2x^2)+(2x\times-3x)+(2x\times2)+(4\times2x^2)+(4\times-3x)+(4\times2) \\ 4x^3-6x^2+4x+8x^2-12x+8 \end{gathered}[/tex]
then simplify adding what you can
[tex]\begin{gathered} 4x^3+(-6+8)x^2+(4-12)x+8 \\ \\ \\ 4x^3+2x^2-8x+8 \end{gathered}[/tex]
