document.write( "Question 1040787: which of the following polynomials has a factor of x-1?.
\n" ); document.write( "A) \"p%28x%29=x%5E3%2Bx%5E2-2x%2B1\"
\n" ); document.write( "B) \"q%28x%29=2x%5E3-x%5E2%2Bx-1\"
\n" ); document.write( "c) \"r%28x%29=3x%5E3-x-2\"
\n" ); document.write( "D) \"s%28x%29=-3x%5E3%2B3x%2B1\"
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Algebra.Com's Answer #655696 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
By the remainder theorem, if x-k is factor of p(x), then p(k) = 0.\r
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\n" ); document.write( "\n" ); document.write( "In this case, x-k = x-1, so k = 1. Therefore, if we find a function p(x) such that p(k) = p(1) = 0 then we have found the answer.\r
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\n" ); document.write( "\n" ); document.write( "Essentially we plug in x = 1 into each answer choice. Then we see which results in 0. \r
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\n" ); document.write( "\n" ); document.write( "Let's go through the answer choices one by one. Starting with choice A\r
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\n" ); document.write( "\n" ); document.write( "\"p%28x%29+=+x%5E3%2Bx%5E2-2x%2B1\"
\n" ); document.write( "\"p%281%29+=+1%5E3%2B1%5E2-2%281%29%2B1\" Replace every x with 1
\n" ); document.write( "\"p%281%29+=+1%2B1-2%281%29%2B1\"
\n" ); document.write( "\"p%281%29+=+1%2B1-2%2B1\"
\n" ); document.write( "\"p%281%29+=+1\"\r
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\n" ); document.write( "\n" ); document.write( "Since the result is NOT equal to 0, this means that x-1 is NOT a factor of p(x).\r
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\n" ); document.write( "Now onto choice B. Like before, plug in x = 1 to see if we get a result of 0.\r
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\n" ); document.write( "\n" ); document.write( "\"q%28x%29+=+2x%5E3-x%5E2%2Bx-1\"
\n" ); document.write( "\"q%281%29+=+2%281%29%5E3-%281%29%5E2%2B1-1\" Replace every 'x' with 1
\n" ); document.write( "\"q%281%29+=+2%281%29-1%2B1-1\"
\n" ); document.write( "\"q%281%29+=+2-1%2B1-1\"
\n" ); document.write( "\"q%281%29+=+1\"\r
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\n" ); document.write( "\n" ); document.write( "Again we don't get 0. So choice B is not the answer either.
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\n" ); document.write( "Part C)\r
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\n" ); document.write( "\n" ); document.write( "\"r%28x%29+=+3x%5E3-x-2\"
\n" ); document.write( "\"r%281%29+=+3%281%29%5E3-1-2\" Plug in x = 1
\n" ); document.write( "\"r%281%29+=+3%281%29-1-2\"
\n" ); document.write( "\"r%281%29+=+3-1-2\"
\n" ); document.write( "\"r%281%29+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "We got a result of 0, so x-1 is a factor of r(x). We have our answer. Let's check part D just to complete the problem.
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\n" ); document.write( "Part D)\r
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\n" ); document.write( "\n" ); document.write( "\"s%28x%29+=+-3x%5E3%2B3x%2B1\"
\n" ); document.write( "\"s%281%29+=+-3%281%29%5E3%2B3%281%29%2B1\" Plug in x = 1
\n" ); document.write( "\"s%281%29+=+-3%281%29%2B3%281%29%2B1\"
\n" ); document.write( "\"s%281%29+=+-3%2B3%2B1\"
\n" ); document.write( "\"s%281%29+=+1\"\r
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\n" ); document.write( "\n" ); document.write( "The nonzero result means x-1 is not a factor of s(x)
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\n" ); document.write( "\n" ); document.write( "To summarize, the final answer is Choice C
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