Slope formulae .
(Substitute )
(Product of two sames signs is positive)
(Subtract: )
(Add: )
Slope is .
![\"Slope](\"/userfiles/image/Library/slope_of_a_line.gif\")
![\"\"](\"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=179236976453cda7d5b5986fb1157f8d.png\")
(Substitute ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=33956b325aa04dca7f61b9bda9257f70.png\")
) ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=7f582f3ad8c6e4853047a27ceef7f6a1.png\")
(Product of two sames signs is positive) ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0fb7476dccca650c96ab9da5cb88fe3b.png\")
(Subtract: ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=6e9c90ef79ceb24ec763f7a8ceba42bc.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=641a851186e971d00ca1ba2bbbce39d9.png\")
(Add: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1df5f45b0d71d7c376553f5e578c6aed.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=641a851186e971d00ca1ba2bbbce39d9.png\")
.