Beginning Algebra With Applications, Chapter 2, 2.3, Section 2.3, Problem 96

Translate the phrase "a number plus four added to the difference between three and twice the number" into a variable expression. Then simplify the expression.

$\begin{equation} \begin{aligned} & \text{The unknown number: } n && \text{Assign a variable to one of the number quantities}\\ \\ & \text{Twice the number: } 2n && \text{Use the assigned variable to write an expression for any other unknown quantity.}\\ \\ & \text{The number plus four: } n + 4 \\ \\ & \text{Difference between three and twice the number: } 3 - 2n\\ \\ &= (3-2n) + (n+4) && \text{Use the assigned variable to write the variable expression.}\\ \\ &= 3 - 2n + n + 4 && \text{Combine like terms}\\ \\ &= 7 + n \end{aligned} \end{equation}$