document.write( "Question 494372: 3x+3y=-9
\n" ); document.write( "3x-3y=-21 \n" ); document.write( "

Algebra.Com's Answer #335625 by Maths68(1474) $\"\"$ $\"About$

You can put this solution on YOUR website!
3x+3y=-9 ...........(1)
\n" ); document.write( "3x-3y=-21...........(2)\r
\n" ); document.write( "\n" ); document.write( "Add (1) and (2)
\n" ); document.write( "3x+3y=-9
\n" ); document.write( "3x-3y=-21
\n" ); document.write( "------------
\n" ); document.write( "6x=-30
\n" ); document.write( "x=-30/6
\n" ); document.write( "x=-5
\n" ); document.write( "Put the value of x in either equations (1) or (2)
\n" ); document.write( "3x+3y=-9 ...........(1)
\n" ); document.write( "3(-5)+3y=-9
\n" ); document.write( "-15+3y=-9
\n" ); document.write( "3y=-9+15
\n" ); document.write( "3y=-9+15
\n" ); document.write( "3y=6
\n" ); document.write( "y=6/3
\n" ); document.write( "y=2\r
\n" ); document.write( "\n" ); document.write( "Solution Set (-5,2)\r
\n" ); document.write( "\n" ); document.write( "Check:
\n" ); document.write( "Put the value of x and y in either equations (1) or (2)
\n" ); document.write( "3x-3y=-21...........(2)
\n" ); document.write( "3(-5)-3(2)=-21
\n" ); document.write( "-15-6=-21
\n" ); document.write( "-21=-21\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );