document.write( "Question 147748: use synthetic division to show that the number given to the right of the equation is a solution of the equation, then solve the polynomial equation.
\n" ); document.write( "x^3+2x^2-11x-12=0;-4\r
\n" ); document.write( "\n" ); document.write( "a){3,1,-4}
\n" ); document.write( "b){3.-1.-4}
\n" ); document.write( "c){-3,1,-4)
\n" ); document.write( "d){-3,-1,-4}
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Algebra.Com's Answer #108116 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "First set up the synthetic division table by placing the test zero (which in this case is -4) in the upper left corner and placing the coefficients of the function to the right of the test zero.\n" ); document.write( "\n" ); document.write( "
-4|12-11-12
|
\r
\n" ); document.write( "\n" ); document.write( "Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 1)\r
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-4|12-11-12
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1
\r
\n" ); document.write( "\n" ); document.write( " Multiply -4 by 1 and place the product (which is -4) right underneath the second coefficient (which is 2)\r
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-4|12-11-12
|-4
1
\r
\n" ); document.write( "\n" ); document.write( " Add -4 and 2 to get -2. Place the sum right underneath -4.\r
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-4|12-11-12
|-4
1-2
\r
\n" ); document.write( "\n" ); document.write( " Multiply -4 by -2 and place the product (which is 8) right underneath the third coefficient (which is -11)\r
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-4|12-11-12
|-48
1-2
\r
\n" ); document.write( "\n" ); document.write( " Add 8 and -11 to get -3. Place the sum right underneath 8.\r
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-4|12-11-12
|-48
1-2-3
\r
\n" ); document.write( "\n" ); document.write( " Multiply -4 by -3 and place the product (which is 12) right underneath the fourth coefficient (which is -12)\r
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-4|12-11-12
|-4812
1-2-3
\r
\n" ); document.write( "\n" ); document.write( " Add 12 and -12 to get 0. Place the sum right underneath 12.\r
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-4|12-11-12
|-4812
1-2-30
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\n" ); document.write( "\n" ); document.write( "Since the last column adds to zero, we have a remainder of zero. This means that -4 is a solution of the equation\r
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\n" ); document.write( "\n" ); document.write( "Now lets look at the bottom row of coefficients:\r
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\n" ); document.write( "\n" ); document.write( "The first 3 coefficients (1,-2,-3) form the quotient\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2+-+2x+-+3\"\r
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\n" ); document.write( "\n" ); document.write( "So \"%28x%5E3+%2B+2x%5E2+-+11x+-+12%29%2F%28x%2B4%29=x%5E2+-+2x+-+3\"\r
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\n" ); document.write( "\n" ); document.write( "Basically \"x%5E3+%2B+2x%5E2+-+11x+-+12\" factors to \"%28x%2B4%29%28x%5E2+-+2x+-+3%29\"\r
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\n" ); document.write( "\n" ); document.write( "Now lets solve \"x%5E2+-+2x+-+3=0\":\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%281%29%28-3%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=-2\", and \"c=-3\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+%28-2%29%5E2-4%281%29%28-3%29+%29%29%2F%282%281%29%29\" Negate \"-2\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+4-4%281%29%28-3%29+%29%29%2F%282%281%29%29\" Square \"-2\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+4--12+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-3%29\" to get \"-12\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+4%2B12+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%284--12%29\" as \"sqrt%284%2B12%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+16+%29%29%2F%282%281%29%29\" Add \"4\" to \"12\" to get \"16\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%28+16+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+4%29%2F%282%29\" Take the square root of \"16\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B+4%29%2F%282%29\" or \"x+=+%282+-+4%29%2F%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%286%29%2F%282%29\" or \"x+=++%28-2%29%2F%282%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+3\" or \"x+=+-1\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are:\r
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\n" ); document.write( "\n" ); document.write( "\"x=-4\", \"x+=+3\" or \"x+=+-1\" \r
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