document.write( "Question 802909: I am very confused on using the substitution and elimination method on linear equations. Can you please explain it to me? \n" ); document.write( "
Algebra.Com's Answer #484052 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
I will solve a simple problem by both methods. See if you can walk through\r
\n" ); document.write( "\n" ); document.write( "Elimination method\r
\n" ); document.write( "\n" ); document.write( "2 x + 1 y = 20 .............1
\n" ); document.write( "
\n" ); document.write( "3 x -4 y = 8 .............2
\n" ); document.write( "Eliminate y
\n" ); document.write( "multiply (1)by 4
\n" ); document.write( "Multiply (2) by 1
\n" ); document.write( "8 x 4 y = 80
\n" ); document.write( "3 x -4 y = 8
\n" ); document.write( "Add the two equations
\n" ); document.write( "11 x = 88
\n" ); document.write( "/ 11
\n" ); document.write( "x = 8
\n" ); document.write( "plug value of x in (1)
\n" ); document.write( "2 x + 1 y = 20
\n" ); document.write( "16 + y = 20
\n" ); document.write( " y = 20 -16
\n" ); document.write( " y = 4
\n" ); document.write( " y = 4 \r
\n" ); document.write( "\n" ); document.write( "Substitution Method\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2 x + 1 y = 20 .............1
\n" ); document.write( "1 y = 20 + -2 x
\n" ); document.write( "/ 1 =
\n" ); document.write( " y = 20 -2 x
\n" ); document.write( "3 x -4 y = 8 .....................2
\n" ); document.write( "Substitute y in (2)
\n" ); document.write( "3 x -4 ( 20 + -2 x ) = 8
\n" ); document.write( "3 x -80 + 8 x = 8
\n" ); document.write( "3 x 8 x = 88
\n" ); document.write( "11 x = 88
\n" ); document.write( "/ 11
\n" ); document.write( "x= 8
\n" ); document.write( "Plug the value of x in (1)
\n" ); document.write( "2 x + 1 y = 20
\n" ); document.write( "2 * 8 + 1 y = 20
\n" ); document.write( "16 + 1 y = 20
\n" ); document.write( "1 y = 4
\n" ); document.write( "/ 1
\n" ); document.write( "y= 4
\n" ); document.write( "m.ananth@hotmail.ca \r
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