document.write( "Question 839719: when twice a number is subtracted from the square of the number, the result is 99. determine the number \n" ); document.write( "
Algebra.Com's Answer #505807 by Theo(13342)\"\" \"About 
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your equation is x^2 - 2x = 99
\n" ); document.write( "subtract 99 from both sides of this equation to get:
\n" ); document.write( "x^2 - 2x - 99 = 0
\n" ); document.write( "factor to get:
\n" ); document.write( "(x - 11) * (x + 9) = 0
\n" ); document.write( "solve for x to get:
\n" ); document.write( "x = 11 or x = -9\r
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\n" ); document.write( "\n" ); document.write( "since there are no restrictions on the sign of the answer, both answers are good.
\n" ); document.write( "the graph of the equation is shown below:\r
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\n" ); document.write( "\n" ); document.write( "\"graph%28600%2C600%2C-20%2C20%2C-150%2C150%2Cx%5E2-2x-99%29\"\r
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\n" ); document.write( "\n" ); document.write( "the solution to the equation are the roots of the equation which is where the graph of the equation crosses the x-axis.\r
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\n" ); document.write( "\n" ); document.write( "your original equation is x^2 - 2x = 99
\n" ); document.write( "when x = 11, this becomes 121 - 22 = 99 which becomes 99 = 99.
\n" ); document.write( "when x = -9, this becomes 81 + 18 = 99 which becomes 99 = 99.
\n" ); document.write( "both solutions are good.
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