The expression is \
The sum is unchanged no matter how one groups the numbers.
This illustrates the Multiplication property of -1: .
Question illustrates Multiplication property of -1.
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=dc2ed5ba971f669f80f9db373a484925.png\")
\
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=5a6d01e3395f87abaa919053c31f8c23.png\")
.![\"\"](\"/userfiles/image/steps_images/solution.JPG\")