Observe the graph:
The graph is a translation of the graph of down units.
So, the equation is .
The equation is .
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4ed2ba46506d7193da1d0de95ee76db8.png\")
down ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2a06887749c014f55973fb0163eb3e52.png\")
units.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=18eaabb51e2f3994602a7b757ab1f4fd.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=18eaabb51e2f3994602a7b757ab1f4fd.png\")
.