document.write( "Question 116121: 2x squared + 10x = -1 \n" ); document.write( "
Algebra.Com's Answer #84443 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "\"2x%5E2%2B10x=-1\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2%2B10x%2B1=0\" Move all of the terms to the left side\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( "Starting with the general quadratic\r
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\n" ); document.write( "\n" ); document.write( "\"ax%5E2%2Bbx%2Bc=0\"\r
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\n" ); document.write( "\n" ); document.write( "the general solution using the quadratic equation is:\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29\"\r
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\n" ); document.write( "\n" ); document.write( "So lets solve \"2%2Ax%5E2%2B10%2Ax%2B1=0\" ( notice \"a=2\", \"b=10\", and \"c=1\")\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B-+sqrt%28+%2810%29%5E2-4%2A2%2A1+%29%29%2F%282%2A2%29\" Plug in a=2, b=10, and c=1\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B-+sqrt%28+100-4%2A2%2A1+%29%29%2F%282%2A2%29\" Square 10 to get 100 \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B-+sqrt%28+100%2B-8+%29%29%2F%282%2A2%29\" Multiply \"-4%2A1%2A2\" to get \"-8\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B-+sqrt%28+92+%29%29%2F%282%2A2%29\" Combine like terms in the radicand (everything under the square root)\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B-+2%2Asqrt%2823%29%29%2F%282%2A2%29\" Simplify the square root (note: If you need help with simplifying the square root, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B-+2%2Asqrt%2823%29%29%2F4\" Multiply 2 and 2 to get 4\r
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\n" ); document.write( "\n" ); document.write( "So now the expression breaks down into two parts\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-10+%2B+2%2Asqrt%2823%29%29%2F4\" or \"x+=+%28-10+-+2%2Asqrt%2823%29%29%2F4\"\r
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\n" ); document.write( "\n" ); document.write( "Now break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"x=-10%2F4%2B2%2Asqrt%2823%29%2F4\" or \"x=-10%2F4-2%2Asqrt%2823%29%2F4\"\r
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\n" ); document.write( "\n" ); document.write( "Simplify\r
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\n" ); document.write( "\n" ); document.write( "\"x=-5+%2F+2%2Bsqrt%2823%29%2F2\" or \"x=-5+%2F+2-sqrt%2823%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "So these expressions approximate to\r
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\n" ); document.write( "\n" ); document.write( "\"x=-0.10208423834364\" or \"x=-4.89791576165636\"\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are:\r
\n" ); document.write( "\n" ); document.write( "\"x=-0.10208423834364\" or \"x=-4.89791576165636\"\r
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\n" ); document.write( "\n" ); document.write( "Notice when we graph \"2%2Ax%5E2%2B10%2Ax%2B1\", we get:\r
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\n" ); document.write( "\n" ); document.write( "when we use the root finder feature on a calculator, we find that \"x=-0.10208423834364\" and \"x=-4.89791576165636\".So this verifies our answer
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