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)![]() ![]() 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 \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |