document.write( "Question 117161: solve the equation using the -b +/- square root of b squared-4(a)(c)divided by 2a\r
\n" ); document.write( "\n" ); document.write( "1. I know the formula I just cannot figure this out.\r
\n" ); document.write( "\n" ); document.write( " x squared = 196\r
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\n" ); document.write( "\n" ); document.write( "x squared -4x +2 = 0
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Algebra.Com's Answer #85196 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
#1\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2=196\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-196=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 \"x%5E2-196=0\" (note: since the polynomial does not have an \"x\" term, the 2nd coefficient is zero. In other words, b=0. So that means the polynomial really looks like \"x%5E2%2B0%2Ax-196=0\" notice \"a=1\", \"b=0\", and \"c=-196\")\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+%280%29%5E2-4%2A1%2A-196+%29%29%2F%282%2A1%29\" Plug in a=1, b=0, and c=-196\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+0-4%2A1%2A-196+%29%29%2F%282%2A1%29\" Square 0 to get 0 \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+0%2B784+%29%29%2F%282%2A1%29\" Multiply \"-4%2A-196%2A1\" to get \"784\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%280+%2B-+sqrt%28+784+%29%29%2F%282%2A1%29\" Combine like terms in the radicand (everything under the square root)\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-0+%2B-+28%29%2F%282%2A1%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+=+%280+%2B-+28%29%2F2\" Multiply 2 and 1 to get 2\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+=+%280+%2B+28%29%2F2\" or \"x+=+%28-0+-+28%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "Lets look at the first part:\r
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\n" ); document.write( "\n" ); document.write( "\"x=%280+%2B+28%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x=28%2F2\" Add the terms in the numerator\r
\n" ); document.write( "\n" ); document.write( "\"x=14\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So one answer is\r
\n" ); document.write( "\n" ); document.write( "\"x=14\"\r
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\n" ); document.write( "\n" ); document.write( "Now lets look at the second part:\r
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\n" ); document.write( "\n" ); document.write( "\"x=%280+-+28%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x=-28%2F2\" Subtract the terms in the numerator\r
\n" ); document.write( "\n" ); document.write( "\"x=-14\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So another answer is\r
\n" ); document.write( "\n" ); document.write( "\"x=-14\"\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are:\r
\n" ); document.write( "\n" ); document.write( "\"x=14\" or \"x=-14\"\r
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\n" ); document.write( "\n" ); document.write( "Notice when we graph \"x%5E2-196\", we get:\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-24%2C+24%2C+-24%2C+24%2C1%2Ax%5E2%2B0%2Ax%2B-196%29+\"\r
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\n" ); document.write( "\n" ); document.write( "and we can see that the roots are \"x=14\" and \"x=-14\". This verifies our answer\r
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\n" ); document.write( "\n" ); document.write( "#2\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 \"x%5E2-4%2Ax%2B2=0\" ( notice \"a=1\", \"b=-4\", and \"c=2\")\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28--4+%2B-+sqrt%28+%28-4%29%5E2-4%2A1%2A2+%29%29%2F%282%2A1%29\" Plug in a=1, b=-4, and c=2\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+%28-4%29%5E2-4%2A1%2A2+%29%29%2F%282%2A1%29\" Negate -4 to get 4\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16-4%2A1%2A2+%29%29%2F%282%2A1%29\" Square -4 to get 16 (note: remember when you square -4, you must square the negative as well. This is because \"%28-4%29%5E2=-4%2A-4=16\".)\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+16%2B-8+%29%29%2F%282%2A1%29\" Multiply \"-4%2A2%2A1\" to get \"-8\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+sqrt%28+8+%29%29%2F%282%2A1%29\" Combine like terms in the radicand (everything under the square root)\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%284+%2B-+2%2Asqrt%282%29%29%2F%282%2A1%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+=+%284+%2B-+2%2Asqrt%282%29%29%2F2\" Multiply 2 and 1 to get 2\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+=+%284+%2B+2%2Asqrt%282%29%29%2F2\" or \"x+=+%284+-+2%2Asqrt%282%29%29%2F2\"\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=%2B4%2F2%2B2%2Asqrt%282%29%2F2\" or \"x=%2B4%2F2-2%2Asqrt%282%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "Simplify\r
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\n" ); document.write( "\n" ); document.write( "\"x=2%2Bsqrt%282%29\" or \"x=2-sqrt%282%29\"\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=3.41421356237309\" or \"x=0.585786437626905\"\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are:\r
\n" ); document.write( "\n" ); document.write( "\"x=3.41421356237309\" or \"x=0.585786437626905\"\r
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\n" ); document.write( "\n" ); document.write( "Notice when we graph \"x%5E2-4%2Ax%2B2\", 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=3.41421356237309\" and \"x=0.585786437626905\".So this verifies our answer
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