Find $ \left(x-4\right)^2 $ using formula.

$$ (A - B)^2 = \color{blue}{A^2} - 2 \cdot A \cdot B + \color{red}{B^2} $$

where $ A = \color{blue}{ x } $ and $ B = \color{red}{ 4 }$.

$$ \begin{aligned}\left(x-4\right)^2 = \color{blue}{x^2} -2 \cdot x \cdot 4 + \color{red}{4^2} = x^2-8x+16\end{aligned} $$

Multiply each term of $ \left( \color{blue}{x^2-8x+16}\right) $ by each term in $ \left( 2x-1\right) $.

$$ \left( \color{blue}{x^2-8x+16}\right) \cdot \left( 2x-1\right) = 2x^3-x^2-16x^2+8x+32x-16 $$

Combine like terms:

$$ 2x^3 \color{blue}{-x^2} \color{blue}{-16x^2} + \color{red}{8x} + \color{red}{32x} -16 = 2x^3 \color{blue}{-17x^2} + \color{red}{40x} -16 $$

Multiply each term of $ \left( \color{blue}{2x^3-17x^2+40x-16}\right) $ by each term in $ \left( x+2\right) $.

$$ \left( \color{blue}{2x^3-17x^2+40x-16}\right) \cdot \left( x+2\right) = 2x^4+4x^3-17x^3-34x^2+40x^2+80x-16x-32 $$

Combine like terms:

$$ 2x^4+ \color{blue}{4x^3} \color{blue}{-17x^3} \color{red}{-34x^2} + \color{red}{40x^2} + \color{green}{80x} \color{green}{-16x} -32 = 2x^4 \color{blue}{-13x^3} + \color{red}{6x^2} + \color{green}{64x} -32 $$