Since the line is raising the slope is positive.
Next, find the slope.
Substitute 8 for y2, 1 for y1, 12 for x2, and 4 for x1 in slope formula.
(subtract: )
Slope is positive and slope is .
![\"slope](\"http://c4anything.com/userfiles/image/Library/slope_of_a_line.gif\")
![\"\"](\"http://c4anything.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"http://c4anything.com/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=7c8d6d692199d3924ba3b2f9869d0b94.png\")
![\"\"](\"/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8429b1c188f4fbc6377f3925831bdade.png\")
![\"\"](\"/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a47b984aecf9d83c5aa3995340f2d1e3.png\")
(subtract: ![\"\"](\"/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=3d68825451aca0861f7bb20c040721e5.png\")
)![\"\"](\"http://c4anything.com/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0a753423ef1fc2251a6f3d19611c84ec.png\")
.