Substitute in rate of change formula.
(Subtract: ) \ \
(Apply additive identity property: )
The rate of change is .
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in rate of change formula.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=3798e8075d30e9621c8eb5f8ec7956c9.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ac44a73d449c18913c905ebf3f90f7be.png\")
(Subtract: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=30bdc5da7b68af16b269c2c0f3c85434.png\")
) \ \
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a0185d5e0736c71369b08db64747da00.png\")
(Apply additive identity property: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=367f983ef1df72673815401c0398961a.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
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.