document.write( "Question 658460: The units digit of a number is 4 times the tens digit. If 54 is added to the number, the digits will be interchanged. Find the number. \n" ); document.write( "
Algebra.Com's Answer #410285 by kevwill(135)\"\" \"About 
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Let x by the tens digit and y be the units digit. Then from the first sentence:
\n" ); document.write( "y = 4x
\n" ); document.write( "And from the second sentence:
\n" ); document.write( "10x + y + 54 = 10y + x
\n" ); document.write( "Substituting y = 4x into the second equation gives:
\n" ); document.write( "10x + 4x + 54 = 10*(4x) + x
\n" ); document.write( "Combining like terms:
\n" ); document.write( "14x + 54 = 41x
\n" ); document.write( "Subtracting 14x from both sides and reversing the equation:
\n" ); document.write( "27x = 54
\n" ); document.write( "Dividing both sides by 27:
\n" ); document.write( "x = 2
\n" ); document.write( "So x = 2, y = 4*2 = 8, and the number is 28. 28 + 54 = 82 \n" ); document.write( "
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