document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=499649>Question 499649</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Prove<BR>\n" );
document.write( "(a+b)/2 = a + (a-b)/2\r<BR>\n" );
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document.write( "Its basically pre-algebra but i am having a hard time wrapping my head around it this morning. i can see it is true, but cannot prove it.  The reason behind it is in computer science a+b could overflow the register and provide false results. So you could do a/2 + b/2, but that uses division twice which is slower. i am still sitting here with a pen and paper trying to figure it out.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #337816 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=337816\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Prove<BR>\n" );
document.write( "(a+b)/2 = a + (a-b)/2<BR>\n" );
document.write( "Multiply by 2<BR>\n" );
document.write( "a+b = 2a + a-b<BR>\n" );
document.write( "a+b = 3a - b  Not equal in general<BR>\n" );
document.write( "Or -2a = -2b<BR>\n" );
document.write( "a = b<BR>\n" );
document.write( "True only if a = b<BR>\n" );
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