The expression is .
(Substitute a = 4 and b = 8)
(Multiply: )
= 20 (Add: 12 + 8 = 20)
The value of expression is 20.
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.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ab47f03fde0678356a6090fc1050916a.png\")
(Substitute a = 4 and b = 8)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4cb47d7b59d36449048ea3dc829a7f14.png\")
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)![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")