Beginning Algebra With Applications, Chapter 2, Review Exercises, Section Review Exercises, Problem 34

Simplify $2x + 3[ x - 2(4-2x)]$

$
\begin{equation}
\begin{aligned}
&= 2x +3 [x - 2(4) - (-2)(2x)] && \text{Use the Distributive Property}\\
\\
&= 2x + 3[x - 2(4) + (2 \cdot 2) x] && \text{Use the Associative Property of Multiplication to group factors}\\
\\
&= 2x + 3[x - 8 + 4x] && \text{Simplify}\\
\\
&= 2x + 3[5x - 8] && \text{Combine like terms}\\
\\
&= 2x +3(5x) - 3(8) && \text{Again, by using the Distributive Property}\\
\\
&=2x + (3 \cdot 5)x - 3(8) && \text{Use again the Associative Property of Multiplication to group factors}\\
\\
&= 2x + 15x - 24 && \text{Simplify}\\
\\
&= 17x - 24 && \text{Combine like terms}
\end{aligned}
\end{equation}
$