document.write( "Question 1088858: If x+2 is a factor of x^3 - ax- 6,then find the remainder when 2x^3+ax^2-6x+9 is divided by x+1.
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Algebra.Com's Answer #703256 by ikleyn(52788)\"\" \"About 
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\n" ); document.write( "If x+2 is a factor of x^3 - ax- 6,then find the remainder when 2x^3+ax^2-6x+9 is divided by x+1.
\n" ); document.write( "Please help me with this question.
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\n" ); document.write( "\n" ); document.write( "Let me do it in a way in how it SHOULD BE DONE.\r
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document.write( "1.  If (x+2) is a factor of \"x%5E3+-ax+-+6\", then, according to the Remainder theorem, the number -2 is the root of the polynomial p(x) = \"x%5E3+-ax+-+6\".\r\n" );
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document.write( "    In other words, p(-2) = 0,  which means\r\n" );
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document.write( "    \"%28-2%29%5E3-a%2A%28-2%29+-+6\" = 0,   or, simplifying,\r\n" );
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document.write( "    -8 + 2a - 6 = 0,   or   2a = 8 + 6 = 14  ====>  a = \"14%2F2\" = 7.\r\n" );
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document.write( "3.  Hence, the second polynomial is \r\n" );
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document.write( "    q(x) = \"2x%5E3+%2B+7x%5E2+-+6x+%2B+9\".\r\n" );
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document.write( "    Then,  again, due to the Remainder theorem, the remainder of division q(x) by (x+1) is equal to the value q(-1), i.e.\r\n" );
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document.write( "     q(-1) = \"2%2A%28-1%29%5E3+%2B+7%2A%28-1%29%5E2+-+6%2A%28-1%29+%2B+9\" = 2*(-1) + 7*1 + 6 + 9 = 20.\r\n" );
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document.write( "Answer. The remainder of division the second polynomial by (x+1) is 20.\r\n" );
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\n" ); document.write( "The remainder theorem:\r
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document.write( "    1. The remainder of division the polynomial  \"f%28x%29\"  by the binomial  \"x-a\"  is equal to the value  \"f%28a%29\"  of the polynomial. \r\n" );
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document.write( "    2. The binomial  \"x-a\"  divides the polynomial  \"f%28x%29\"  if and only if the value of  \"a\"  is the root of the polynomial  \"f%28x%29\",  i.e.  \"f%28a%29+=+0\".\r\n" );
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document.write( "    3. The binomial  \"x-a\"  factors the polynomial  \"f%28x%29\"  if and only if the value of  \"a\"  is the root of the polynomial  \"f%28x%29\",  i.e.  \"f%28a%29+=+0\".\r\n" );
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\n" ); document.write( "\n" ); document.write( "See the lesson\r
\n" ); document.write( "\n" ); document.write( "    - Divisibility of polynomial f(x) by binomial (x-a) and the Remainder theorem \r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this online textbook under the topic
\n" ); document.write( "\"Divisibility of polynomial f(x) by binomial (x-a). The Remainder theorem\".\r
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\n" ); document.write( "Ignore writing by @josgarithmetic. His way IS NOT the method for solving such problems.\r
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\n" ); document.write( "\n" ); document.write( "It is not his level of knowledge and is not his area of expertise.\r
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