What are all the ordered triples of positive integers (x,y,z) with x<y<z, such that their product is four times their sum?
An Excel + Macro solution which by exhaustive random analysis (range 0 to 1000) came up with the folowing solutions:
<TABLE style="WIDTH: 162pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=216 border=0 x:str>
<COLGROUP>
<COL style="WIDTH: 54pt" span=3 width=72>
<TBODY>
<TR style="HEIGHT: 14.25pt" height=19>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; WIDTH: 54pt; BORDER-BOTTOM: #d4d0c8; HEIGHT: 14.25pt; BACKGROUND-COLOR: transparent" align=right width=72 height=19 x:num>
1
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; WIDTH: 54pt; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right width=72 x:num>
5
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; WIDTH: 54pt; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right width=72 x:num>
24
</TD></TR>
<TR style="HEIGHT: 14.25pt" height=19>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; HEIGHT: 14.25pt; BACKGROUND-COLOR: transparent" align=right height=19 x:num>
1
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
6
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
14
</TD></TR>
<TR style="HEIGHT: 14.25pt" height=19>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; HEIGHT: 14.25pt; BACKGROUND-COLOR: transparent" align=right height=19 x:num>
1
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
8
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
9
</TD></TR>
<TR style="HEIGHT: 14.25pt" height=19>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; HEIGHT: 14.25pt; BACKGROUND-COLOR: transparent" align=right height=19 x:num>
2
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
3
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
10
</TD></TR>
<TR style="HEIGHT: 14.25pt" height=19>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; HEIGHT: 14.25pt; BACKGROUND-COLOR: transparent" align=right height=19 x:num>
2
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
4
</TD>
<TD style="BORDER-RIGHT: #d4d0c8; BORDER-TOP: #d4d0c8; BORDER-LEFT: #d4d0c8; BORDER-BOTTOM: #d4d0c8; BACKGROUND-COLOR: transparent" align=right x:num>
6
</TD></TR></TBODY></TABLE>
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Posted by Fernando
on 2007-11-23 14:31:19 |