Find $ \left(j+2\right)^2 $ using formula.

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

where $ A = \color{blue}{ j } $ and $ B = \color{red}{ 2 }$.

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

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

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

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

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

Multiply $ \color{blue}{j} $ by $ \left( j^2+4j+4\right) $ $$ \color{blue}{j} \cdot \left( j^2+4j+4\right) = j^3+4j^2+4j $$

Remove the parentheses by changing the sign of each term within them.

$$ - \left( 16-8f+f^2 \right) = -16+8f-f^2 $$

Combine like terms:

$$ j^3-f^2+4j^2+8f+4j-16 = j^3-f^2+4j^2+8f+4j-16 $$