document.write( "Question 426896: The difference of the digits of a 2-digit number is 5. If the digits are reversed, the new number is 7 greater than twice the original number. What is the units digit of the original number? \n" ); document.write( "

Algebra.Com's Answer #296869 by mananth(16949) $\"\"$ $\"About$

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y-x =5
\n" ); document.write( "10y+x= 2(10x+y)+7
\n" ); document.write( "10y+x=20x+2y+7
\n" ); document.write( "8y-19x=7\r
\n" ); document.write( "\n" ); document.write( "-x+y=5 .............1
\n" ); document.write( "-19x+8y=7.............2
\n" ); document.write( "
\n" ); document.write( "multiply (1)by -8
\n" ); document.write( "Multiply (2) by 1
\n" ); document.write( "8x-8y=-40
\n" ); document.write( "-19x+8y=7
\n" ); document.write( "
\n" ); document.write( "Add the two equations
\n" ); document.write( "
\n" ); document.write( "-11x = -33
\n" ); document.write( "
\n" ); document.write( "/-11
\n" ); document.write( "
\n" ); document.write( "x= 3
\n" ); document.write( "
\n" ); document.write( "plug value of x in (1)
\n" ); document.write( "
\n" ); document.write( "-x+y=5
\n" ); document.write( "-3+y=5
\n" ); document.write( "y=5+3
\n" ); document.write( "y=8
\n" ); document.write( "The number is 38 \n" ); document.write( "

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