document.write( "Question 1086139: Suppose a and x satisfy x^2 + (a-(1/a))x - 1 = 0. Solve for x in terms of a.\r
\n" ); document.write( "\n" ); document.write( "*That's a quadratic in x
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Algebra.Com's Answer #700302 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
Use a substitution for ease,
\n" ); document.write( "\"C=a-1%2Fa\"
\n" ); document.write( "Complete the square,
\n" ); document.write( "\"x%5E2%2BCx-1=0\"
\n" ); document.write( "\"%28x%5E2%2BCx%2B%28C%2F2%29%5E2%29=1%2B%28C%2F2%29%5E2\"
\n" ); document.write( "\"%28x%2BC%2F2%29%5E2=1%2BC%5E2%2F4\"
\n" ); document.write( "\"x%2BC%2F2=0+%2B-+sqrt%28%284%2BC%5E2%29%2F4%29\"
\n" ); document.write( "\"x=-C%2F2+%2B-+sqrt%284%2BC%5E2%29%2F2\"
\n" ); document.write( "So then,
\n" ); document.write( "\"C%2F2=a%2F2-1%2F%282a%29\"
\n" ); document.write( "\"C%2F2=a%5E2%2F%282a%29-1%2F%282a%29\"
\n" ); document.write( "\"C%2F2=%28a%5E2-1%29%2F%282a%29\"
\n" ); document.write( "and
\n" ); document.write( "\"C=%28a%5E2-1%29%2Fa\"
\n" ); document.write( "\"C%5E2=%28a%5E2-1%29%5E2%2Fa%5E2\"
\n" ); document.write( "\"4%2BC%5E2=4a%5E2%2Fa%5E2%2B%28a%5E2-1%29%5E2%2Fa%5E2\"
\n" ); document.write( "\"4%2BC%5E2=%284a%5E2%2B%28a%5E2-1%29%5E2%29%2Fa%5E2\"
\n" ); document.write( "\"4%2BC%5E2=%284a%5E2%2Ba%5E4-2a%5E2%2B1%29%2Fa%5E2\"
\n" ); document.write( "\"4%2BC%5E2=%28a%5E4%2B2a%5E2%2B1%29%2Fa%5E2\"
\n" ); document.write( "\"4%2BC%5E2=%28a%5E2%2B1%29%5E2%2Fa%5E2\"
\n" ); document.write( "So then substituting,
\n" ); document.write( "\"2x=-C+%2B-+sqrt%284%2BC%5E2%29\"
\n" ); document.write( "\"2x=%281-a%5E2%29%2Fa+%2B-+sqrt%28%28a%5E2%2B1%29%5E2%2Fa%5E2%29\"
\n" ); document.write( "\"2x=%281-a%5E2%29%2Fa+%2B-+%28a%5E2%2B1%29%2Fa\"
\n" ); document.write( "\"2xa=1-a%5E2+%2B-+%28a%5E2%2B1%29\"
\n" ); document.write( "\"Positive\" solution:
\n" ); document.write( "\"2xa=1-a%5E2+%2B+a%5E2%2B1\"
\n" ); document.write( "\"2xa=2\"
\n" ); document.write( "\"highlight%28x=1%2Fa%29\"
\n" ); document.write( "\"Negative\" solution:
\n" ); document.write( "\"2xa=1-a%5E2+-+a%5E2-1%29\"
\n" ); document.write( "\"2xa=-2a%5E2\"
\n" ); document.write( "\"highlight%28x=-a%29\"
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