document.write( "Question 637292: (2-sqrt7)^2= ? it says to simplify expression thanks for your help! \n" ); document.write( "

Algebra.Com's Answer #401563 by jsmallt9(3758) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"%282-sqrt%287%29%29%5E2\"$
\n" ); document.write( "IMPORTANT: Exponents so not distribute! So simplifying this expression is not done by squaring the 2 and squaring the square root!!

\n" ); document.write( "To simplify this expression we can either use FOIL on $\"%282-sqrt%287%29%29%282-sqrt%287%29%29\"$ or use the $\"%28a-b%29%5E2+=+a%5E2-2ab%2Bb%5E2\"$ pattern.

\n" ); document.write( "I prefer using the pattern. With an \"a\" of \"2\" and a \"b\" of \" $\"sqrt%287%29\"$ \", the pattern tells us that
\n" ); document.write( " $\"%282-sqrt%287%29%29%5E2\"$
\n" ); document.write( "would be
\n" ); document.write( " $\"%282%29%5E2-2%282%29%28sqrt%287%29%29%2B%28sqrt%287%29%29%5E2\"$
\n" ); document.write( "which simplifies as follows:
\n" ); document.write( " $\"4+-+4sqrt%287%29+%2B+7\"$
\n" ); document.write( " $\"11+-+4sqrt%287%29\"$ \n" ); document.write( "

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