document.write( "Question 1028367: Use one of the product-to-sum formulas to write the given
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Algebra.Com's Answer #643470 by Edwin McCravy(20060) $\"\"$ $\"About$

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document.write( "Add the two equations:\r\n" );
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document.write( "Get\r\n" );
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document.write( "Multiply both sides by 1/2\r\n" );
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document.write( "Swap sides:\r\n" );
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document.write( " <--product-to-sum formula\r\n" );
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document.write( "Let , \r\n" );
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document.write( "Edwin

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