document.write( "Question 96250: Solve the equation:\r
\n" ); document.write( "\n" ); document.write( "y^2 - 2y -24 = 0
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Algebra.Com's Answer #70073 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let's use the quadratic formula to solve for y:\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( "\"ay%5E2%2Bby%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( "\"y+=+%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 \"y%5E2-2%2Ay-24=0\" ( notice \"a=1\", \"b=-2\", and \"c=-24\")\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%28--2+%2B-+sqrt%28+%28-2%29%5E2-4%2A1%2A-24+%29%29%2F%282%2A1%29\" Plug in a=1, b=-2, and c=-24\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%282+%2B-+sqrt%28+%28-2%29%5E2-4%2A1%2A-24+%29%29%2F%282%2A1%29\" Negate -2 to get 2\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%282+%2B-+sqrt%28+4-4%2A1%2A-24+%29%29%2F%282%2A1%29\" Square -2 to get 4 (note: remember when you square -2, you must square the negative as well. This is because \"%28-2%29%5E2=-2%2A-2=4\".)\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%282+%2B-+sqrt%28+4%2B96+%29%29%2F%282%2A1%29\" Multiply \"-4%2A-24%2A1\" to get \"96\"\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%282+%2B-+sqrt%28+100+%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( "\"y+=+%282+%2B-+10%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( "\"y+=+%282+%2B-+10%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( "\"y+=+%282+%2B+10%29%2F2\" or \"y+=+%282+-+10%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=%282+%2B+10%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=12%2F2\" Add the terms in the numerator\r
\n" ); document.write( "\n" ); document.write( "\"y=6\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So one answer is\r
\n" ); document.write( "\n" ); document.write( "\"y=6\"\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=%282+-+10%29%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=-8%2F2\" Subtract the terms in the numerator\r
\n" ); document.write( "\n" ); document.write( "\"y=-4\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So another answer is\r
\n" ); document.write( "\n" ); document.write( "\"y=-4\"\r
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\n" ); document.write( "\n" ); document.write( "So our solutions are:\r
\n" ); document.write( "\n" ); document.write( "\"y=6\" or \"y=-4\"\r
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\n" ); document.write( "\n" ); document.write( "Notice when we graph \"x%5E2-2%2Ax-24\" (just replace y with x), we get:\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-14%2C+16%2C+-14%2C+16%2C1%2Ax%5E2%2B-2%2Ax%2B-24%29+\"\r
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\n" ); document.write( "\n" ); document.write( "and we can see that the roots are \"y=6\" and \"y=-4\". This verifies our answer
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