The linear function is y = 1400x
(Substitute 5 for x)
(Multiply: ) \
\
The sound travel 7200 meters in 5 seconds.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f851643b83557e15020c2c924be3c5bc.png\")
(Substitute 5 for x)![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cb515b66afdf9fb14e78bcd9666672b8.png\")
(Multiply: ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=71877adab425769643f9273f7166ff8b.png\")
) \
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")