document.write( "Question 66138: The sum of the digits of a two-digit number is 7. The tens digit is 7 more than twice the units digit. Find the number. \n" ); document.write( "

Algebra.Com's Answer #46854 by josmiceli(19441) $\"\"$ $\"About$

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The number is $\"10a+%2B+b\"$ The digits are a and b
\n" ); document.write( " $\"a+%2B+b+=+7\"$
\n" ); document.write( " $\"a+=+2b+%2B+7\"$
\n" ); document.write( " $\"b+=+7+-+a\"$
\n" ); document.write( " $\"a+=+2%287+-+a%29+%2B+7\"$
\n" ); document.write( " $\"a+=+14+-+2a+%2B+7\"$
\n" ); document.write( " $\"a+=+21+-+2a\"$
\n" ); document.write( " $\"3a+=+21\"$
\n" ); document.write( " $\"a+=+7\"$
\n" ); document.write( " $\"7+%2B+b+=+7\"$
\n" ); document.write( " $\"b+=+0\"$
\n" ); document.write( "The number is 70
\n" ); document.write( "If b were 1 or greater, a would turn out to be 9 or higher, and
\n" ); document.write( "a can't be greater than 7
\n" ); document.write( " $\"a+=+2%2A1+%2B+7\"$
\n" ); document.write( " $\"a+=+9\"$ \n" ); document.write( "

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