document.write( "Question 303960: Use te clue to find the secret two-digit number. The sum of the digits is 9. The product of the digits is 18. The number is between 40 and 90.
\n" ); document.write( "What is the number? \n" ); document.write( "
Algebra.Com's Answer #217789 by ankor@dixie-net.com(22740)\"\" \"About 
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The sum of the digits is 9. The product of the digits is 18. The number is between 40 and 90.
\n" ); document.write( "What is the number?
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\n" ); document.write( "Let 10x + y = the two digit number
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\n" ); document.write( "\"The sum of the digits is 9.\"
\n" ); document.write( "x + y = 9
\n" ); document.write( "y = (9-x)
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\n" ); document.write( "The product of the digits is 18.
\n" ); document.write( "x * y = 18
\n" ); document.write( "Replace y with (9-x)
\n" ); document.write( "x(9-x) = 18
\n" ); document.write( "-x^2 + 9x = 18
\n" ); document.write( "-x^2 + 9x - 18 = 0
\n" ); document.write( "Multiply by -1 to change the signs
\n" ); document.write( "x^2 - 9x + 18 = 0
\n" ); document.write( "Factors easily to
\n" ); document.write( "(x-6)(x-3) = 0
\n" ); document.write( "x = 6, (no. is greater than 40)
\n" ); document.write( "then
\n" ); document.write( "y = 3
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\n" ); document.write( "The number is between 40 and 90.
\n" ); document.write( "What is the number? It's 63 \n" ); document.write( "
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