\
The expression is
.
\
(Definition of negative exponent)
\
The solution is
.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=60709674171b0f2db751d9fc66373f54.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=19a2d7279c7169c232cc67c9f57d5c9e.png\")
(Definition of negative exponent)![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=26809df2098cf0ccf76d43672964e5fd.png\")
.