document.write( "Question 82999: Okay I really need someone's help with this one. Substitution confuses me. I need to solve the system by substitution:\r
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document.write( "3x+3y=9
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document.write( "y=2x-12 \n" );
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Algebra.Com's Answer #59558 by checkley75(3666)![]() ![]() ![]() You can put this solution on YOUR website! y=2x-12 now substitute (2x-12) for y in the other equation thus: \n" ); document.write( "3x+3(2x-12)=9 \n" ); document.write( "3x+6x-36=9 \n" ); document.write( "9x=9+36 \n" ); document.write( "9x=45 \n" ); document.write( "x=45/9 \n" ); document.write( "x=5 answer. \n" ); document.write( "y=2*5-12 \n" ); document.write( "y=10-12 \n" ); document.write( "y=-2 answer. \n" ); document.write( "proof \n" ); document.write( "3*5+3*-2=9 \n" ); document.write( "15-6=9 \n" ); document.write( "9=9 \n" ); document.write( " |