The expression is .
(Definition of negative exponents: )
.
The expreesion using only positive terms is .
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0da2e1979e20ab94635a1036764d55b7.png\")
. ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c8134c357799571e9431f7dc8069fe5a.png\")
(Definition of negative exponents: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9d22e0e2f4e711de11d5c531ed4a669e.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=caac71b4311b4e1bd83dfc3393f47b56.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8277fa4677b3dba38aa3f3bacd501b62.png\")
.