From the word problem and the table, we know that:
[tex]\text{ If }\frac{640\text{ mi}}{10\text{ gal}},\text{ then }\frac{x\text{ mi}}{1\text{ gal}}[/tex]
Then, we can write and solve the following equation:
[tex]\begin{gathered} \frac{640\text{ mi}}{10\text{ gal}}=\frac{x}{1\text{ gal}} \\ \text{ Multiply by 1 gal from both sides} \\ \frac{640\text{ mi}}{10\text{ gal}}\cdot1\text{ gal}=\frac{x}{1\text{ gal}}\cdot1\text{ gal} \\ \frac{640\text{ mi}}{10\text{ gal}}\cdot1\text{ gal}=x \\ \frac{640\text{ mi}}{10}\cdot1=x \\ \frac{640\text{ mi}}{10}=x \\ 64\text{ mi }=x \end{gathered}[/tex]
Therefore, the unit rate is 64 miles per gallon.
