document.write( "Question 369085: Solve using substitution.\r
\n" ); document.write( "\n" ); document.write( "2x + y = -9 so this is what I tried... 2x - 2x -9 = -9
\n" ); document.write( " -2x -2x
\n" ); document.write( " -2x -9 = -2x -9
\n" ); document.write( " +9 +9
\n" ); document.write( " -2x = -2x???? What am I doing wrong?\r
\n" ); document.write( "\n" ); document.write( "y= -2x -9
\n" ); document.write( "

Algebra.Com's Answer #263017 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
You're not doing anything wrong except that you only have 1 equation with 2 unknowns.
\n" ); document.write( "You can only solve for one variable in terms of the other variable.
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