document.write( "Question 28816: Use elimination to solve:
\n" ); document.write( "3x-y=15
\n" ); document.write( "5x+y=9\r
\n" ); document.write( "\n" ); document.write( "this is what I got\r
\n" ); document.write( "\n" ); document.write( " 3x-y=15
\n" ); document.write( "(+)5x+y=9
\n" ); document.write( "__________
\n" ); document.write( "8x+0=24\r
\n" ); document.write( "\n" ); document.write( "8x=24\r
\n" ); document.write( "\n" ); document.write( "8x/8= 24/8
\n" ); document.write( "x=3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3(2)-y=15
\n" ); document.write( "6-y=15
\n" ); document.write( "6-y-6=15-6
\n" ); document.write( "-y=9\r
\n" ); document.write( "\n" ); document.write( "-y/-1= 9/-1\r
\n" ); document.write( "\n" ); document.write( "y= -9
\n" ); document.write( "I do not know what I did wrong????????
\n" ); document.write( "

Algebra.Com's Answer #15718 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
You correctly solved for \"x\", but you did
\n" ); document.write( "not correctly substitute that value into
\n" ); document.write( "the 1st original equation to solve for \"y\".
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "
\n" );