# 8.11: Drive Away

**Drive Away – Interpret Graphs and Write Functions Rules**

**Teacher Notes**

Each distance-time graph shows two lines representing the speeds of two drivers. Students first interpret the Fact to identify the driver of interest. Next they complete a Time-Distance table of values for the first 6 hours travelled. By inspecting the table of values and identifying relationships between entries in each line of the table, they write a rule that shows how the Distance , or number of miles traveled, relates to the amount of time , or number of hours of travel.

**Solutions:**

**Drive Away 1**

- 15 mph

**Drive Away 2**

- 20 mph

**Drive Away – Interpret Graphs and Write Functions Rules**

**Fact: The graph shows the speeds of drivers, Axel and Bush, on city roads. Bush is traveling faster than Axel.**

- What was Bush’s speed in miles per hour?
- Complete the table to show total number of miles traveled by Bush at that speed.
- Let represent number of hours and represent distance in number of miles. Write a rule to show how the number of miles is related to number of hours .

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**Drive Away 1**

**Fact: The graph shows the speeds of drivers, Harold and French. Harold didn’t travel as fast as French.**

- What was Harold’s speed in miles per hour?
- Complete the table to show total number of miles traveled by Harold at that speed.
- Let represent number of hours and represent distance in number of miles. Write a rule to show how the number of miles is related to number of hours .

____________________

**Drive Away 2**

**Fact: The graph shows the speeds of drivers, Roberts and Clark. Roberts drove 10 mph slower than Clark.**

- What was Clark’s speed in miles per hour?
- Complete the table to show total number of miles traveled by Clark at that speed.
- Let represent number of hours and represent distance in number of miles. Write a rule to show how the number of miles is related to number of hours .

____________________

*Extra for Experts:***Drive Away – Interpret Graphs and Write Functions Rules**

**Drive Away Extra 1**

**Fact: The graph shows the speeds of drivers, Marx and Stevens. Marx drove 5 mph faster than Stevens.**

- What was Marx’s speed in miles per hour?
- Complete the table to show total number of miles traveled by Marx at that speed.

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**Drive Away Extra 2**

**Fact: The graph shows the speeds of drivers, Ellsworth and Stewart. The speed limit on Highway 999 is 55 mph. Ellsworth obeyed the speed limit. Stuart did not.**

- What was Ellsworth’s speed in miles per hour?
- Complete the table to show total number of miles traveled by Ellsworth at that speed.

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**Solutions:**

**Drive Away Extra 1**

- 25 mph

**Drive Away Extra 2**

- 50 mph