document.write( "Question 21423: 2x+y=8
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document.write( "y+3z=5
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document.write( "z+2w=1
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document.write( "5w+3x=9
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document.write( "solve the equations for x,y,w,z \n" );
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Algebra.Com's Answer #10321 by josmiceli(19441)![]() ![]() You can put this solution on YOUR website! 2x + y = 8 \n" ); document.write( "y + 3z = 5\r \n" ); document.write( "\n" ); document.write( "(a) solve each equation for y\r \n" ); document.write( "\n" ); document.write( "y = 8 - 2x \n" ); document.write( "y = 5 - 3z\r \n" ); document.write( "\n" ); document.write( "(b) solve the third equation for z\r \n" ); document.write( "\n" ); document.write( "z + 2w = 1 \n" ); document.write( "z = 1 - 2w\r \n" ); document.write( "\n" ); document.write( "from (a) \n" ); document.write( "8 - 2x = 5 - 3z \n" ); document.write( "substitute (1-2w) for z, the result from (b) \n" ); document.write( "8 - 2x = 5 - 3(1-2w) \n" ); document.write( "8 - 2x = 5 - 3(1-2w) \n" ); document.write( "8 - 2x = 5 - 3 + 6w\r \n" ); document.write( "\n" ); document.write( "(c) 8 - 2x = 2 + 6w\r \n" ); document.write( "\n" ); document.write( "solve the fourth equation for x \n" ); document.write( "5w + 3x = 9 \n" ); document.write( "3x = 9 - 5w \n" ); document.write( "x = 3 - (5/3)w \n" ); document.write( "substitute this result into (c)\r \n" ); document.write( "\n" ); document.write( "8 -2(3 - (5/3)w) = 2 + 6w \n" ); document.write( "8 - 6 + (10/3)w = 2 + 6w \n" ); document.write( "8 - 6 - 2 = (8/3)w \n" ); document.write( "0 = (8/3)w \n" ); document.write( "w = 0 \n" ); document.write( "from the fourth equation, \n" ); document.write( "5(0) +3x = 9 \n" ); document.write( "x = 3 \n" ); document.write( "from the 1st equation, \n" ); document.write( "2(3) + y = 8 \n" ); document.write( "y = 2 \n" ); document.write( "from the 2nd equation, \n" ); document.write( "(2) + 3z = 5 \n" ); document.write( "z = 1\r \n" ); document.write( "\n" ); document.write( "so, \n" ); document.write( "x = 3 \n" ); document.write( "y = 2 \n" ); document.write( "z = 1 \n" ); document.write( "w = 0 \n" ); document.write( "plug these values back into all four equations to verify them\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |