The expression is .
(Apply commutative property of addition: )
(Subtract: )
The standard form of the expression is .
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.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d5f97c236c65430fd73789d888094794.png\")
(Apply commutative property of addition: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1e5ef353d6f211250e43610c18cb2697.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=698334fbf0eeb624b525c9a71db37d2c.png\")
(Subtract: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=aa5efeb49b1a9a80e7afde4be7ece6bb.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
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.