document.write( "Question 1046935: A two-digit number is 72 less than the number obtained by reversing the digits. Find the number. \n" ); document.write( "

Algebra.Com's Answer #662381 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+t+\"$ = the tens digit
\n" ); document.write( "Let $\"+u+\"$ = the units digit
\n" ); document.write( "--------------------------
\n" ); document.write( " $\"+10t+%2B+u+=+10u+%2B+t+-+72+\"$
\n" ); document.write( " $\"+72+=+-9t+%2B+9u+\"$
\n" ); document.write( " $\"+-t+%2B+u+=+8+\"$
\n" ); document.write( "The only thing that fits here is:
\n" ); document.write( " $\"+t+=+1+\"$
\n" ); document.write( " $\"+u+=+9+\"$
\n" ); document.write( "because if $\"+u+\"$ is $\"8\"$ or less,
\n" ); document.write( "then $\"t\"$ becomes zero or negative
\n" ); document.write( "-------------------------------
\n" ); document.write( "The number is 19
\n" ); document.write( "-------------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+10t+%2B+u+=+10u+%2B+t+-+72+\"$
\n" ); document.write( " $\"+10%2A1+%2B+9+=+10%2A9+%2B+1+-+72+\"$
\n" ); document.write( " $\"+19+=+91+-+72+\"$
\n" ); document.write( " $\"+19+=+19+\"$
\n" ); document.write( "OK \n" ); document.write( "

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