document.write( "Question 449477: solve by the subst\r
\n" ); document.write( "\n" ); document.write( "Solve by the substitution method.
\n" ); document.write( "9x+3y=-30
\n" ); document.write( "-3x+y=20
\n" ); document.write( "What is the solution of the system?
\n" ); document.write( "The solution is____?
\n" ); document.write( "(Type an ordered pair)\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #309188 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
9x+3y=-30 .............1
\n" ); document.write( "y=20+3x ---------2
\n" ); document.write( "/1=
\n" ); document.write( "y=20+3x
\n" ); document.write( "Plug the value of y in (1)
\n" ); document.write( "9x+3(20+3x)=-30
\n" ); document.write( "9x+60+9x=-30
\n" ); document.write( "9x+9x= -30 -60
\n" ); document.write( "18x=-90
\n" ); document.write( "/18
\n" ); document.write( "x=-5
\n" ); document.write( "Plug the value of x in (1)
\n" ); document.write( "9x+3y=-30
\n" ); document.write( "9*-5+3y=-30
\n" ); document.write( "-45+3y=-30
\n" ); document.write( "3y=15
\n" ); document.write( "/3
\n" ); document.write( "y=5
\n" ); document.write( "(-5,5) \n" ); document.write( "
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