document.write( "Question 551877: use the echelon method to solve:
\n" ); document.write( "x+y=16
\n" ); document.write( "6x-y=33
\n" ); document.write( "cant seem to get it right
\n" ); document.write( "

Algebra.Com's Answer #360000 by KMST(5328)\"\" \"About 
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I have not heard of an echelon method, but I have heard translations of the word echelon from the French into other languages to refer to a strategy to solve systems of linear equations.
\n" ); document.write( "You want to keep an equation involving both variables and replace the other equation with a combination of the two where one of the variables has been eliminated.
\n" ); document.write( "I would keep \"x%2By=16\" because it's nice and simple and replace the other equation, using the sum of the two
\n" ); document.write( "\"x%2By%2B6x-y=16%2B33\" --> \"7x=49\"
\n" ); document.write( "The system is now
\n" ); document.write( "\"x%2By=16\"
\n" ); document.write( "\"7x=49\"
\n" ); document.write( "Even better, we can further simplify, dividing both sides by 7.
\n" ); document.write( "\"7x=49\" --> \"x=7\"
\n" ); document.write( "So we could say that we now have the system
\n" ); document.write( "\"x%2By=16\"
\n" ); document.write( "\"x=7\"
\n" ); document.write( "Then substituting we get \"7%2By=16\" --> \"y=16-7=9\"
\n" ); document.write( "Maybe you were trying to eliminate instead of y to give your modified system the same shape as the one in the book.
\n" ); document.write( "We can do that too, if you get points for eliminating variables in alphabetical order.
\n" ); document.write( "Just multiply \"x%2By=16\" times -6 to get \"-6x-6y=-96\" and add it to
\n" ); document.write( "\"6x-y=33\" to get
\n" ); document.write( "\"-6x-6y%2B6x-y=-96%2B33\" --> \"-7y=-63\"
\n" ); document.write( "Then you could simplify it by dividing both sides by -7 to get
\n" ); document.write( "\"y=9\"
\n" ); document.write( "
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