document.write( "Question 429582: Use Linear Combinations to solve the Linear System\r
\n" ); document.write( "\n" ); document.write( "2-7x=9y
\n" ); document.write( "2y-4x=6 \r
\n" ); document.write( "\n" ); document.write( "I dont get how you use linear combinations to solve this. My book doesn't explain things into detail and my teacher doesn't either. Thanks! \n" ); document.write( "
Algebra.Com's Answer #298367 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
Use Linear Combinations to solve the Linear System\r
\n" ); document.write( "\n" ); document.write( "2-7x=9y
\n" ); document.write( "2y-4x=6
\n" ); document.write( "-----------
\n" ); document.write( "Not sure what you mean by combinations. I'll use elimination, which in a way combines the 2 eqns.
\n" ); document.write( "2-7x=9y
\n" ); document.write( "2y-4x=6
\n" ); document.write( "--------
\n" ); document.write( "9y+7x = 2 eqn 1
\n" ); document.write( "1y-2x = 3 eqn 2 divided by 2
\n" ); document.write( "----------
\n" ); document.write( "9y + 7x = 2 eqn 1
\n" ); document.write( "9y -18x = 27 eqn 2 divided by 2 then x9
\n" ); document.write( "---------- Subtract
\n" ); document.write( "0y +25x = -25
\n" ); document.write( "x = -1
\n" ); document.write( "---------
\n" ); document.write( "1y-2x = 3 Sub for x
\n" ); document.write( "y + 2 = 3
\n" ); document.write( "y = 1
\n" ); document.write( "That's it.\r
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