Slope of the two non vertical lines is .
Replace in slope formula.
(Subtract: )
(Simplify)
The slope .
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=3113839441e3480450ece8dbc4b861da.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1eb9fda85ad2504e1feb91a4e37998ee.png\")
in slope formula.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=733e2c4135e5a826d5ee404a160014b7.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8829a3d83d59863e447929b7a2049437.png\")
(Subtract: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f31c669678c429bfe3f84c7af179b867.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1821769ac90aabd42af527fec214d106.png\")
(Subtract: ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=efca035849e2b804417c9f539117b742.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=834cafcac4a6bfe86881887235cc5ab1.png\")
(Simplify)![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=834cafcac4a6bfe86881887235cc5ab1.png\")
.