The expression is .
(The product of two same signs is positive)
(Multiply: )
(The product of two different signs is negative)
The product is .
![\"\"](\"../../../userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=5fe2a304d2f84c8c5f769d2d2a855473.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=286eb325d5a15ce5c957b5b1fdf14999.png\")
(The product of two same signs is positive)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=671365a6253766b60bf039a4dad2f321.png\")
(Multiply: ![\"\"](\"plugins/fckeditor_wiris/integration/showimage.php?formula=1ba458ff8c72f64dd4ea91512c1d07b3.png\")
)![\"\"](\"../../../userfiles/image/steps_images/step2.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=dc7f849404641aae0d87b2137c619a48.png\")
(The product of two different signs is negative)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c6a4c60716a74a9137ed0c48f64f6cb6.png\")
(Multiply: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=99ccdf8511dc28b01e4ed4242719b38d.png\")
)![\"\"](\"../../../userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=6011577ded02cb1a1e8eec1d5e212d20.png\")
.