document.write( "Question 137891: 3x+2y=-2
\n" ); document.write( "2x-3z=1
\n" ); document.write( "0.4x-0.5z=-2.1
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #100855 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
3x + 2y =-2
\n" ); document.write( "2x - 3z = 1
\n" ); document.write( "0.4x-0.5z=-2.1
\n" ); document.write( ":
\n" ); document.write( "Multiply the 3rd equation by 10 and arrange to:
\n" ); document.write( "2x + 2y + 0z = -2
\n" ); document.write( "2x + 0y - 3z = 1
\n" ); document.write( "4x + 0y - 5z = -21
\n" ); document.write( ":
\n" ); document.write( "Multiply the 2nd equation by -2, add to the 3rd equation
\n" ); document.write( "-4x + 0y + 6z = -2
\n" ); document.write( "+4x + 0y - 5z = -21
\n" ); document.write( "----------------------addition eliminates x
\n" ); document.write( "0x + 0y + z = -23
\n" ); document.write( "z = -23
\n" ); document.write( ":
\n" ); document.write( "Find x using the 2nd equation
\n" ); document.write( "2x - 3(-23) = 1
\n" ); document.write( "2x + 69 = 1
\n" ); document.write( "2x = 1 - 69
\n" ); document.write( "2x = -68
\n" ); document.write( "x = $\"%28-68%29%2F2\"$
\n" ); document.write( "x = -34
\n" ); document.write( ":
\n" ); document.write( "Find y using the 1st equation:
\n" ); document.write( "3(-34) +2y = -2
\n" ); document.write( "-102 + 2y = -2
\n" ); document.write( "2y = 102 - 2
\n" ); document.write( "2y = $\"100%2F2\"$
\n" ); document.write( "y = +50
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solution using original 3rd equation:
\n" ); document.write( "0.4x - 0.5z = -2.1
\n" ); document.write( ".4(-34) -.5(-23) =
\n" ); document.write( "-13.6 + 11.5 = -2.1; confirms our solution
\n" ); document.write( " \n" ); document.write( "

\n" );