## Thinking Mathematically (6th Edition)

The difference is of $1252\text{ billion dollars}$
Consider the given bar graph. From the image above, the number corresponding to $2007$year are, Money collected was $2568$ billion dollars Money spent was$2729$ billion dollars So, the total difference in amount is, \begin{align} & \text{Diff }=\text{money collected - money spent} \\ & =2568-2729 \\ & =-161 \end{align} Thus, the difference is of$-161\,\,\text{billion}\,\text{dollars}$. Since it is negative, the budget is a deficit. From the image above, the number corresponding to $2009$ year are, Money collected was $2105$ billion dollars Money spent was$3518$ billion dollars So, the total difference in amount is, \begin{align} & \text{Diff }=\text{money collected - money spent} \\ & =2105-3518 \\ & =-1413 \end{align} Thus, the difference is of$-\text{1413}\,\,\text{billion}\,\text{dollars}$. Since it is negative, the budget is a deficit. So, the total difference in amount is, \begin{align} & \text{Diff }=~-161-\left( -1413 \right) \\ & =-161+1413 \\ & =1252 \end{align} Thus, difference is of $\text{1252}\,\,\text{billion}\,\text{dollars}$.