document.write( "Question 118218: Hi, I am having some problems understanding the steps using quadratic formula. Can you please show me in detailed steps how to solve this problem.\r
\n" ); document.write( "\n" ); document.write( "x^2 – 3x – 23 = 5\r
\n" ); document.write( "\n" ); document.write( "My directions say to solve using the quadratic formula.\r
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\n" ); document.write( "Patti
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Algebra.Com's Answer #86322 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"x%5E2-3x-23=5\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-3x-23-5=0\" Subtract 5 from both sides. \r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-3x-28=0\" Combine like terms\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%5E2-3%2Ax-28=0\" ( notice \"a=1\", \"b=-3\", and \"c=-28\")\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28--3+%2B-+sqrt%28+%28-3%29%5E2-4%2A1%2A-28+%29%29%2F%282%2A1%29\" Plug in a=1, b=-3, and c=-28\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+%28-3%29%5E2-4%2A1%2A-28+%29%29%2F%282%2A1%29\" Negate -3 to get 3\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+9-4%2A1%2A-28+%29%29%2F%282%2A1%29\" Square -3 to get 9 (note: remember when you square -3, you must square the negative as well. This is because \"%28-3%29%5E2=-3%2A-3=9\".)\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+9%2B112+%29%29%2F%282%2A1%29\" Multiply \"-4%2A-28%2A1\" to get \"112\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+sqrt%28+121+%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+=+%283+%2B-+11%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+=+%283+%2B-+11%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+=+%283+%2B+11%29%2F2\" or \"x+=+%283+-+11%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=%283+%2B+11%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x=14%2F2\" Add the terms in the numerator\r
\n" ); document.write( "\n" ); document.write( "\"x=7\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So one answer is\r
\n" ); document.write( "\n" ); document.write( "\"x=7\"\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=%283+-+11%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"x=-8%2F2\" Subtract the terms in the numerator\r
\n" ); document.write( "\n" ); document.write( "\"x=-4\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So another answer is\r
\n" ); document.write( "\n" ); document.write( "\"x=-4\"\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are:\r
\n" ); document.write( "\n" ); document.write( "\"x=7\" or \"x=-4\"\r
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\n" ); document.write( "\n" ); document.write( "Notice when we graph \"x%5E2-3%2Ax-28\", we get:\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-14%2C+17%2C+-14%2C+17%2C1%2Ax%5E2%2B-3%2Ax%2B-28%29+\"\r
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\n" ); document.write( "\n" ); document.write( "and we can see that the roots are \"x=7\" and \"x=-4\". This verifies our answer
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