document.write( "Question 1187475: 12(x^2+1/x^2)-56(x+1/x)+89=0 \n" ); document.write( "
Algebra.Com's Answer #818445 by greenestamps(13198)\"\" \"About 
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\n" ); document.write( "Fun problem...!

\n" ); document.write( "Here is the key:

\n" ); document.write( "\"x%5E2%2B1%2Fx%5E2+=+%28x%5E2%2B2%2B1%2Fx%5E2%29-2+=+%28x%2B1%2Fx%29%5E2-2\"

\n" ); document.write( "Use that to rewrite the first expression in parentheses and you end up with a quadratic equation with \"x+1/x\" as the \"variable\".

\n" ); document.write( "Solve that equation for x+1/x and you end up solving two quadratic equations that each have two real solutions, giving you four solutions to the given equation.

\n" ); document.write( "\"12%28x%5E2%2B1%2Fx%5E2%29-56%28x%2B1%2Fx%29%2B89=0\"
\n" ); document.write( "\"12%28x%5E2%2B2%2B1%2Fx%5E2%29-12%282%29-56%28x%2B1%2Fx%29%2B89=0\"
\n" ); document.write( "\"12%28x%2B1%2Fx%29%5E2-24-56%28x%2B1%2Fx%29%2B89=0\"
\n" ); document.write( "\"12%28x%2B1%2Fx%29%5E2-56%28x%2B1%2Fx%29%2B65=0\"

\n" ); document.write( "That's a quadratic equation in the \"variable\" x+1/x -- solve it by factoring.

\n" ); document.write( "\"%282%28x%2B1%2Fx%29-5%29%286%28x%2B1%2Fx%29-13%29=0\"

\n" ); document.write( "\"x%2B1%2Fx=5%2F2\" or \"x%2B1%2Fx=13%2F6\"

\n" ); document.write( "Solve each of those equations....

\n" ); document.write( "\"x%2B1%2Fx=5%2F2\"
\n" ); document.write( "\"2x%2B2%2Fx=5\"
\n" ); document.write( "\"2x-5%2B2%2Fx=0\"
\n" ); document.write( "\"2x%5E2-5x%2B2=0\"
\n" ); document.write( "\"%282x-1%29%28x-2%29=0\"
\n" ); document.write( "\"x=1%2F2\" or \"x=2\"

\n" ); document.write( "There are two solutions; note that they are reciprocals of each other. That makes sense, since the equation can be written as a quadratic with \"variable\" (x+1/x) -- if x=2 then 1/x=1/2; and if x=1/2 then 1/x=2.

\n" ); document.write( "\"x%2B1%2Fx=13%2F6\"
\n" ); document.write( "\"6x%2B6%2Fx=13\"
\n" ); document.write( "\"6x-13%2B6%2Fx=0\"
\n" ); document.write( "\"6x%5E2-13x%2B6=0\"
\n" ); document.write( "\"%282x-3%29%283x-2%29=0\"
\n" ); document.write( "\"x=3%2F2\" or \"x=2%2F3\"

\n" ); document.write( "There are two more solutions which are also reciprocals of each other.

\n" ); document.write( "ANSWER: There are 4 solutions: x=2 or x=1/2; and x=3/2 and x=2/3

\n" ); document.write( "Here is a graph of the given equation, showing the four zeros at 1/2, 2/3, 3/2, and 2.

\n" ); document.write( "\"graph%28600%2C200%2C-1%2C4%2C-1%2C1%2C12%28x%5E2%2B1%2Fx%5E2%29-56%28x%2B1%2Fx%29%2B89%29\"

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