document.write( "Question 625271: Place the indicated product in the proper location on the grid.
\n" ); document.write( "(x^2 + 4)(x^2 - 4) \n" ); document.write( "

Algebra.Com's Answer #393456 by jsmallt9(3758) $\"\"$ $\"About$

You can put this solution on YOUR website!
One could just use FOIL to multiply this. But it's faster if you realize that
\n" ); document.write( " $\"%28x%5E2+%2B+4%29%28x%5E2+-+4%29\"$
\n" ); document.write( "exactly matches the pattern of the left side of
\n" ); document.write( " $\"%28a%2Bb%29%28a-b%29+=+a%5E2-b%5E2\"$
\n" ); document.write( "with the \"a\" replaced by $\"x%5E2\"$ and the \"b\" being replaced by \"4\". So, according to the right side of the pattern, the product will be:
\n" ); document.write( " $\"%28x%5E2%29%5E2-%284%29%5E2\"$
\n" ); document.write( "which simplifies to:
\n" ); document.write( " $\"x%5E4-16\"$

\n" ); document.write( "P.S. You get the same answer if you use FOIL correctly. \n" ); document.write( "

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