document.write( "Question 632953: Complete the trinomial so it is a perfect square. x^2 + ___+ 64
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Algebra.Com's Answer #398559 by Edwin McCravy(20055)\"\" \"About 
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document.write( "x² + ___ + 64\r\n" );
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document.write( "We know it must end up as the square of the sum of the square roots of\r\n" );
document.write( "the given first and third terms.  The square root of x² is x and the \r\n" );
document.write( "square root of 64 is 8. We multiply out the square of their sum, which\r\n" );
document.write( "is (x+8)²:\r\n" );
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document.write( " (x+8)² = (x+8)(x+8) = x² + 8x + 8x + 64 = x² + 16x + 64.\r\n" );
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document.write( "So we see now that the middle term has to be the same as that middle term,\r\n" );
document.write( "which is 16x:\r\n" );
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document.write( "x² + 16x + 64\r\n" );
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document.write( "You can do that or you can memorize the rule.  The middle term is always\r\n" );
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document.write( "TWICE THE PRODUCT OF THE TWO SQUARE ROOTS.\r\n" );
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document.write( "The two square roots are x and 8.  Their product is 8x and twice that is 16x.\r\n" );
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document.write( "The first way is when you can't remember the rule.\r\n" );
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document.write( "Edwin
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