The expression is .
(Substitute: )
(The product of two different signs is negative)
(Multiply: )
The solution is .
![\"\"](\"../../../userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=89849f84dcfdb9cbb227ca4f4d58abeb.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d6280aaa55825bf8ec848858a05b1441.png\")
(Substitute: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9634156dd3be6325c84bc52ed67b1004.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8df98df08ba39effb4a2c17ed895802b.png\")
(The product of two different signs is negative)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f50ec323aeaa54ff2aa79342ca9d11fd.png\")
(Multiply: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=64177a40754bc9a457195cb43c5cd490.png\")
)![\"\"](\"../../../userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9531e46c62943fb5e56009de09c5a881.png\")
.