document.write( "Question 21423: 2x+y=8
\n" ); document.write( "y+3z=5
\n" ); document.write( "z+2w=1
\n" ); document.write( "5w+3x=9
\n" ); document.write( "solve the equations for x,y,w,z
\n" ); document.write( "

Algebra.Com's Answer #10321 by josmiceli(19441)\"\" \"About 
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( "
\n" );