document.write( "Question 1155559: Solving:\r
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document.write( " 5 x-3y = 18
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document.write( " -3 x-3y = -12 \r
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document.write( "Using Substitution Method.\r
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document.write( "Expressing x as a function of y (from the first equation) x = (18 +3y)/5\r
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document.write( "Substituting this expression into the second equation:\r
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document.write( " -3 (18 -3y)/5-3y = -12 \r
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document.write( "Why is this not -3(18+3y)/5-3y = -12 ?
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Algebra.Com's Answer #778165 by Alan3354(69443)![]() ![]() You can put this solution on YOUR website! 5 x-3y = 18 \n" ); document.write( "-3 x-3y = -12 \n" ); document.write( "================= \n" ); document.write( "Substitution is not a good choice here, tho you might be instructed to use it. \n" ); document.write( "==== \n" ); document.write( "If you mean: \n" ); document.write( "5x -3y = 18 \n" ); document.write( "-3x-3y = -12 \n" ); document.write( "---------------------- Subtract \n" ); document.write( "8x = 30 \n" ); document.write( "x = 15/4 \n" ); document.write( "----- \n" ); document.write( "Sub for x in either equation and find y. \n" ); document.write( "-3 x-3y = -12 \n" ); document.write( "x + y = 4 \n" ); document.write( "y = 4 - 15/4 \n" ); document.write( "y = 1/4 \n" ); document.write( " |