The expression is .
(Apply associative property of addition: )
(Add: )
The simplified expression is 40 + a.
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![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a43ec15cec27c0f725227dcd5e38164c.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=93156fa1e42f7d3bf7237dfcac57fbc5.png\")
(Apply associative property of addition: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0ac940ec69cdcbea7470db4d2cb12516.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=7af48a4411ff9a658c10c72f74bdf512.png\")
(Add: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d35b064ef2b9acd1621acc71bc96f5c8.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")