document.write( "Question 180671This question is from textbook Algebra 1
\n" ); document.write( ": 2m + n = 1
\n" ); document.write( "m - n = 8 \n" ); document.write( "

Algebra.Com's Answer #135400 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
There are 2 equations and 2 unknowns,
\n" ); document.write( "so it is solvable. If there were more
\n" ); document.write( "unknowns than equations it would be
\n" ); document.write( "unsolvable
\n" ); document.write( "(1) $\"2m+%2B+n+=+1\"$
\n" ); document.write( "(2) $\"m+-+n+=+8\"$
\n" ); document.write( "Just add the equations
\n" ); document.write( " $\"2m+%2B+m+%2B+n+-+n+=+1+%2B+8\"$
\n" ); document.write( " $\"3m+=+9\"$
\n" ); document.write( "Divide both sides by $\"3\"$
\n" ); document.write( " $\"%283m%29%2F3+=+9%2F3\"$
\n" ); document.write( " $\"m+=+3\"$
\n" ); document.write( "As long as I do the same thing to both
\n" ); document.write( "sides, the equation is still true.
\n" ); document.write( "Put $\"m+=+3\"$ back into (2)
\n" ); document.write( " $\"3+-+n+=+8\"$
\n" ); document.write( "Subtract $\"3\"$ from both sides
\n" ); document.write( " $\"-n+=+8+-+3\"$
\n" ); document.write( " $\"-n+=+5\"$
\n" ); document.write( "Multiply both sides by $\"-1\"$
\n" ); document.write( " $\"n+=+-5\"$
\n" ); document.write( "The solution is $\"m+=+3\"$ and $\"n+=+-5\"$
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