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=8a705bd7edbec40f8ca0a7eb0c1e5d79.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=27e5ec1689051409f293da77b828f502.png\")
(Substitute ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c5908cd1c6a2df9457651b39d61c7740.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4b4fc9d15a87c3118f25be94c3d92abb.png\")
(The product of two different signs is negative)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4554d8bab6e755f8ad6d0f7ff5490ac9.png\")
(Multiply: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=87d3c244d8fcda95b7c3a9a022da045f.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ce820b8066a03b9758be41ca651bc67a.png\")
.