\
The expression is
.
\
\
Apply square of a difference formula:
.
\
\
.
\
The value of
.
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![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=43dff545dd193330d73faf09ede21e33.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cb3c5fec4f189e56d0e84a8189e677c9.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a45fb49a24009eb4f8977ae3dedd8259.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=e88b7ed32e859466b32efe7676e6080c.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9090a619a2fdd40afb74019d57bf95d5.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
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.