document.write( "Question 389612: Use the quadratic formula to solve the equations:
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Algebra.Com's Answer #276117 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Use the quadratic formula to solve the equations:
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document.write( "    \"0+=+x%5E2+%2B+x+-+20\"\r
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document.write( "Write as\r
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document.write( "\"x%5E2+%2B+x+-+20=0\"\r
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document.write( "and then as\r
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document.write( "\"1%2Ax%5E2+%2B+1%2Ax+%2B+%28-20%29=0\"\r
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document.write( "and compare to this form which you must memorize:\r
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document.write( "\"A%2Ax%5E2+%2B+B%2Ax+%2B+C+=+0\"\r
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document.write( "We see that A=1, B=1, C=-20.  and we substitute into
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document.write( "this formula which you must also memorize:
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document.write( "\"x+=+%28-B+%2B-+sqrt%28+B%5E2-4%2AA%2AC+%29%29%2F%282%2AA%29+\" \r
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document.write( "\"x+=+%28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%2A%281%29%2A%28-20%29+%29%29%2F%282%2A%281%29%29+\"\r
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document.write( "\"x+=+%28-1+%2B-+sqrt%28+1%2B80%29%29%2F2+\"\r
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document.write( "\"x+=+%28-1+%2B-+sqrt%2881%29%29%2F2+\"\r
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document.write( "\"x+=+%28-1+%2B-+9%29%2F2+\"\r
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document.write( "Use the + for the first solution:\r
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document.write( "\"x+=+%28-1+%2B+9%29%2F2+\"\r
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document.write( "\"x+=+8%2F2+\"\r
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document.write( "\"x+=+4\"  That's the first solution.\r
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document.write( "Use the - for the second solution:\r
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document.write( "\"x+=+%28-1+-+9%29%2F2+\"\r
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document.write( "\"x+=+%28-10%29%2F2+\"\r
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document.write( "\"x+=+-5\"  That's the second solution.\r
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document.write( "There are two solutions x = 4 and x = -5.\r
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document.write( "The other one is solved the same way.\r
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document.write( "The solutions to it are x = 3 and x = 2\r
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document.write( "Edwin
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