document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1021264>Question 1021264</A>: <I><SPAN STYLE=\"word-break: break-all;\"> if x and y are odd numbers, then x+y is even\r<BR>\n" );
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document.write( "If x and y are both odd, then x+1 and y-1 are even. But then x+y=(x+1)+(y-1) is the sum of two even numbers, and, therefore, even.\r<BR>\n" );
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document.write( "Is this a valid proof? If so, what type of proof is it because I am confused. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #637022 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=637022\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  if x and y are odd numbers, then x+y is even:: True<BR>\n" );
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document.write( "If x and y are both odd, then x+1 and y-1 are even.:: True<BR>\n" );
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document.write( " But then x+y=(x+1)+(y-1) is the sum of two even numbers<BR>\n" );
document.write( " and, therefore, even:: <BR>\n" );
document.write( "Is this a valid proof? If so, what type of proof is it because I am confused.<BR>\n" );
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document.write( "It shows that \"if x and y are odd, the sum of x+1 and y-1 is even.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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