document.write( "Question 761968: Seven times a two digit no. equals four times the number with digit reversed find the number if the sum of its digits is 3 \n" ); document.write( "

Algebra.Com's Answer #463610 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+u+\"$ = the units digit
\n" ); document.write( "Let $\"+t+\"$ = the tens digit
\n" ); document.write( "-----------------------
\n" ); document.write( "The value of the number is $\"+10t+%2B+u+\"$
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+7%2A%28+10t+%2B+u+%29+=+4%2A%28+10u+%2B+t+%29+\"$
\n" ); document.write( "(2) $\"+t+%2B+u+=+3+\"$
\n" ); document.write( "---------------
\n" ); document.write( "(1) $\"+70t+%2B+7u+=+40u+%2B+4t+\"$
\n" ); document.write( "(1) $\"+66t+=+33u+\"$
\n" ); document.write( "(1) $\"+2t+=+u+\"$
\n" ); document.write( "by substitution:
\n" ); document.write( "(2) $\"+t+%2B+2t+=+3+\"$
\n" ); document.write( "(2) $\"+3t+=+3+\"$
\n" ); document.write( "(2) $\"+t+=+1+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+t+%2B+u+=+3+\"$
\n" ); document.write( "(2) $\"+1+%2B+u+=+3+\"$
\n" ); document.write( "(2) $\"+u+=+2+\"$
\n" ); document.write( "The number is 12
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+7%2A%28+10t+%2B+u+%29+=+4%2A%28+10u+%2B+t+%29+\"$
\n" ); document.write( "(1) $\"+7%2A%28+10%2A1+%2B+2+%29+=+4%2A%28+10%2A2+%2B+1+%29+\"$
\n" ); document.write( "(1) $\"+7%2A12+=+4%2A21+\"$
\n" ); document.write( "(1) $\"+84+=+84+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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