document.write( "Question 536731: Help me solve this by the substitution method: 9m+n=80
\n" ); document.write( " m-3n=12 \n" ); document.write( "

Algebra.Com's Answer #352557 by mananth(16946) $\"\"$ $\"About$

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1 x -3 y = 12 .............1
\n" ); document.write( "1 y = 80 -9 x ---------2
\n" ); document.write( "/ 1 =
\n" ); document.write( " y = 80 -9 x
\n" ); document.write( "Substitute y in (1)
\n" ); document.write( "1 x -3 ( 80 -9 x ) = 12
\n" ); document.write( "1 x -240 + 27 x = 12
\n" ); document.write( "1 x + 27 x = 12 240
\n" ); document.write( "28 x = 252
\n" ); document.write( "/ 28
\n" ); document.write( "x= 9
\n" ); document.write( "Plug the value of x in (1)
\n" ); document.write( "1 x -3 y = 12
\n" ); document.write( "1 * 9 -3 y = 12
\n" ); document.write( "9 -3 y = 12
\n" ); document.write( "-3 y = 3
\n" ); document.write( "/ -3
\n" ); document.write( "y= -1
\n" ); document.write( "m.ananth@hotmail.ca
\n" ); document.write( " \n" ); document.write( "

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