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=5c3abd9ff819e3b06ee44dc160919dab.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=06dda3a01e9800a0fa60015c9d70718d.png\")
(Substitute: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=32542b3df113b5cdbe1fb87a1c9bc295.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=74a2f56db453f3213bd9b6599a272b4a.png\")
(The product of two different signs is negative)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=7daec20d905087b0b6990dc4d02d649f.png\")
(Multiply: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=850a0ff5bd7851d5c08fab8e290e9fc3.png\")
)![\"\"](\"../../../userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cc6b1f116a537a15ac27ad4189e667e0.png\")
.