document.write( "Question 1069018: Please help me solve by completing the square\r
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Algebra.Com's Answer #684259 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "f(x) = 2x² + 12x + 15\r\n" );
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document.write( "We want to get it to the standard form\r\n" );
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document.write( "f(x) = a(x - h)² + k\r\n" );
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document.write( "f(x) = 2x² + 12x + 15\r\n" );
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document.write( "Factor 2 out of the first two terms:\r\n" );
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document.write( "f(x) = 2[x² + 6] + 15\r\n" );
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document.write( "Skip a space on the right of the bracketed expression\r\n" );
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document.write( "f(x) = 2[x² + 6x        ] + 15\r\n" );
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document.write( "To the side, complete the square:\r\n" );
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document.write( "        6(1/2) = 3  <--half of the coefficient of x\r\n" );
document.write( "        3² = 9      <--square that result\r\n" );
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document.write( "Add and subtract the value inside the bracket:\r\n" );
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document.write( "f(x) = 2[x² + 6x + 9 - 9] + 15\r\n" );
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document.write( "Factor the first three terms inside the bracket:\r\n" );
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document.write( "f(x) = 2[(x+3)(x+3) - 9] + 15\r\n" );
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document.write( "Write the factorization as the square of (x+3)\r\n" );
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document.write( "f(x) = 2[(x+3)² - 9] + 15\r\n" );
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document.write( "Distribute the 2 inside the bracket leaving the (x+3)² intact:\r\n" );
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document.write( "f(x) = 2(x+3)² - 18 + 15\r\n" );
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document.write( "Combine like terms:\r\n" );
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document.write( "f(x) = 2(x+3)² - 3\r\n" );
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document.write( "Compare to\r\n" );
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document.write( "f(x) = a(x-h)² + k\r\n" );
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document.write( "The vertex is (h,k) = (-3,-3)\r\n" );
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document.write( "Get a couple of points on each side of\r\n" );
document.write( "the vertex (-3,-3)\r\n" );
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document.write( "  x | y = f(x) \r\n" );
document.write( "  --|---------\r\n" );
document.write( " -5 |  5\r\n" );
document.write( " -4 | -1\r\n" );
document.write( " -3 | -3   <-- vertex\r\n" );
document.write( " -2 | -1\r\n" );
document.write( " -1 |  5\r\n" );
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document.write( "          \r\n" );
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document.write( "Edwin
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