document.write( "Question 271709: solve by substitution
\n" ); document.write( "3m + n =1
\n" ); document.write( "m - 4n = 9 \n" ); document.write( "

Algebra.Com's Answer #198863 by LarissaRichardson(34) $\"\"$ $\"About$

You can put this solution on YOUR website!
3m+n=1
\n" ); document.write( "m-4n=9
\n" ); document.write( "Find what n is in the first equation (we find n because it doesn't have a coefficient and will be easier.)
\n" ); document.write( "3m+n=1
\n" ); document.write( "n=1-3m
\n" ); document.write( "Now that you have found what n is, substitute it in the second equation as:
\n" ); document.write( "m-4(1-3m)=9
\n" ); document.write( "Distribute now:
\n" ); document.write( "m-4+12m=9
\n" ); document.write( "Combine like terms:
\n" ); document.write( "13m=13
\n" ); document.write( "Divide by 13
\n" ); document.write( "m=1\r
\n" ); document.write( "\n" ); document.write( "Now to find n, substitute the m=1 into either equation. I will use the first equation:
\n" ); document.write( "3(1)+n=1
\n" ); document.write( "3+n=1
\n" ); document.write( "Combine like terms
\n" ); document.write( "n=-2\r
\n" ); document.write( "\n" ); document.write( "Now check your answers by plugging them in to the equations:
\n" ); document.write( "3m+n=1
\n" ); document.write( "3(1)+(-2)=1
\n" ); document.write( "3-2=1 YAY!
\n" ); document.write( "Now check your other equation!! \n" ); document.write( "

\n" );