Difference between revisions of "2007 Alabama ARML TST Problems/Problem 1"

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==Solution==
 
==Solution==
<cmath>2000(2000+7)(2000+8)(2000+15)+784=(2000^2+15\cdot 2000+56)(2000^2+15\cdot 2000)+28^2=(2000^2+15\cdot 2000+28)(2000^2+15\cdot 2000+28)-28^2+28^2</cmath>
+
<math>2000(2000+7)(2000+8)(2000+15)+784</math>
  
Thus <math></math>\sqrt{2000\cdot 2007\cdot 2008\cdot 2015+784}=\boxed{4030028}$
+
<math>=(2000^2+15\cdot 2000+56)(2000^2+15\cdot 2000)+28^2</math>
 +
 
 +
<math>=(2000^2+15\cdot 2000+28)(2000^2+15\cdot 2000+28)-28^2+28^2</math>
 +
 
 +
Thus <math>\sqrt{2000\cdot 2007\cdot 2008\cdot 2015+784}=\boxed{4030028}</math>
  
 
==See also==
 
==See also==

Revision as of 12:19, 17 June 2008

Problem

Compute: $\sqrt{2000\cdot 2007\cdot 2008\cdot 2015+784}.$

Solution

$2000(2000+7)(2000+8)(2000+15)+784$

$=(2000^2+15\cdot 2000+56)(2000^2+15\cdot 2000)+28^2$

$=(2000^2+15\cdot 2000+28)(2000^2+15\cdot 2000+28)-28^2+28^2$

Thus $\sqrt{2000\cdot 2007\cdot 2008\cdot 2015+784}=\boxed{4030028}$

See also