document.write( "Question 1199644: Find three consecutive positive even integers such that the
\n" ); document.write( "product of the median and largest integer is 6 less than 21 times
\n" ); document.write( "the smallest integer..
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Algebra.Com's Answer #833599 by math_tutor2020(3816)\"\" \"About 
You can put this solution on YOUR website!

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\n" ); document.write( "\n" ); document.write( "Explanation:\r
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\n" ); document.write( "\n" ); document.write( "Consecutive integers follow one after another.
\n" ); document.write( "Example: 4, 5, 6
\n" ); document.write( "Each adjacent neighboring item has a gap of 1.\r
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\n" ); document.write( "\n" ); document.write( "Consecutive even integers are the same idea, but all of the values must be even.
\n" ); document.write( "Example: 8, 10, 12
\n" ); document.write( "Each adjacent neighboring item has a gap of 2.\r
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\n" ); document.write( "\n" ); document.write( "Let x be a positive even number from the set {2, 4, 6, 8, ...}\r
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\n" ); document.write( "\n" ); document.write( "x = 1st even integer
\n" ); document.write( "x+2 = 2nd even integer = median = middle
\n" ); document.write( "x+4 = 3rd even integer
\n" ); document.write( "The gap from x to x+2 is +2, and the gap from x+2 to x+4 is also +2\r
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\n" ); document.write( "\n" ); document.write( "(x+2)*(x+4) = \"product of median and the largest integer\"
\n" ); document.write( "21x-6 = \"Six less than 21 times the smallest integer\" \r
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\n" ); document.write( "\n" ); document.write( "\"The product of the median and largest integer is 6 less than 21 times the smallest integer\" translates to
\n" ); document.write( "(x+2)*(x+4) = 21x-6\r
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\n" ); document.write( "\n" ); document.write( "We'll expand things out and get everything to one side
\n" ); document.write( "(x+2)*(x+4) = 21x-6
\n" ); document.write( "x^2+6x+8 = 21x-6
\n" ); document.write( "x^2+6x+8-21x+6 = 0
\n" ); document.write( "x^2-15x+14 = 0\r
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\n" ); document.write( "\n" ); document.write( "Then you have a few options at this point.\r
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\n" ); document.write( "\n" ); document.write( "One method is to factor like so:
\n" ); document.write( "x^2-15x+14 = 0
\n" ); document.write( "(x-1)(x-14) = 0
\n" ); document.write( "x-1 = 0 or x-14 = 0
\n" ); document.write( "x = 1 or x = 14\r
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\n" ); document.write( "\n" ); document.write( "We ignore x = 1 since x must be even.
\n" ); document.write( "Therefore, x = 14 is the only solution.\r
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\n" ); document.write( "\n" ); document.write( "Another method of solving:\r
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\n" ); document.write( "\n" ); document.write( "We can apply the quadratic formula
\n" ); document.write( "x^2-15x+14 = 0 is of the form ax^2+bx+c = 0
\n" ); document.write( "where,
\n" ); document.write( "a = 1
\n" ); document.write( "b = -15
\n" ); document.write( "c = 14
\n" ); document.write( "So,
\n" ); document.write( "\"x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-15%29%2B-sqrt%28%28-15%29%5E2-4%281%29%2814%29%29%29%2F%282%281%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2815%2B-sqrt%28225-56%29%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2815%2B-sqrt%28169%29%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2815%2B-++13%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2815%2B13%29%2F%282%29\" or \"x+=+%2815-13%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2828%29%2F%282%29\" or \"x+=+%282%29%2F%282%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+14\" or \"x+=+1\"
\n" ); document.write( "We arrive at the same two solutions found earlier.
\n" ); document.write( "And as mentioned earlier, we ignore x = 1 to go for x = 14.\r
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\n" ); document.write( "\n" ); document.write( "A third method:\r
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\n" ); document.write( "\n" ); document.write( "Graph out y = x^2-15x+14 using a TI calculator, Desmos, or GeoGebra.
\n" ); document.write( "There are tons of options out there so feel free to use your favorite graphing calculator.\r
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\n" ); document.write( "\n" ); document.write( "\"graph%28500%2C500%2C-3%2C16%2C-50%2C50%2C0%2Cx%5E2-15x%2B14%29\"\r
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\n" ); document.write( "\n" ); document.write( "The parabola crosses the x axis at the locations (1,0) and (14,0) which shows that x = 1 and x = 14 are the two solutions or roots.\r
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\n" ); document.write( "\n" ); document.write( "The term \"x intercept\" is another way of saying \"root\" or \"zero of a function\". \r
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\n" ); document.write( "\n" ); document.write( "If x = 14, then,
\n" ); document.write( "x+2 = 14+2 = 16
\n" ); document.write( "x+4 = 14+4 = 18\r
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\n" ); document.write( "\n" ); document.write( "So that's how we arrive at 14, 16, 18 as the final answer.\r
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\n" ); document.write( "\n" ); document.write( "Check:
\n" ); document.write( "median*largest = 16*18 = 288
\n" ); document.write( "21*smallest-6 = 21*14-6 = 288
\n" ); document.write( "This confirms that the equation (x+2)(x+4) = 21x-6 is correct when x = 14, and confirms the final answer.
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