![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Choose any two points on the line and find the rate of change between them.
\We will the points at (60, 10) and (30, 40).
\(60, 10)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8f4e281dce37b6008da3c587098b88c6.png\")
60 tickets sold, 10 tickets avialable.
(30, 40)![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8f4e281dce37b6008da3c587098b88c6.png\")
30 tickets sold, 40 tickets available.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Rate of change = ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c704367ddaaf7f88908ad0bbfa5bcab2.png\")
.
The tickets available changes from 10 to 40 and the tickets sold changes from 60 to 30.
\Rate of change = ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=88937a563148aed43851886e5795740a.png\")
Rate of change = ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=95a585c467179999f9b45ed07597c7e6.png\")
Rate of change = ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c194162d38fbde7e954c39d492b6315c.png\")
. (Divide: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=642901a26fe4e33b5b65d7da7d9f3086.png\")
)
So, the rate of change is ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c194162d38fbde7e954c39d492b6315c.png\")
, or a decrease of 1 ticket available per ticket sold. ![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The rate of change is .