document.write( "Question 1134169: Solve the system of equations by finding a row echelon form for the augmented matrix.
\n" ); document.write( "x - 3y + 3z = 19
\n" ); document.write( "2x -y - 9z= -32
\n" ); document.write( "-5x+10y+z=-21\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #751565 by rothauserc(4718)\"\" \"About 
You can put this solution on YOUR website!
The augmented matrix is
\n" ); document.write( ":
\n" ); document.write( "1 -3 3 19
\n" ); document.write( "2 -1 -9 -32
\n" ); document.write( "-5 10 1 -21
\n" ); document.write( ":
\n" ); document.write( "We perform a series of row operations to achieve row echelon form, let Rn be the nth row of the matrix
\n" ); document.write( ":
\n" ); document.write( "R3 +5R1
\n" ); document.write( ":
\n" ); document.write( "5 -15 15 95
\n" ); document.write( "2 -1 -9 -32
\n" ); document.write( "0 -5 16 74
\n" ); document.write( ":
\n" ); document.write( "R1/5
\n" ); document.write( ":
\n" ); document.write( "1 -3 3 19
\n" ); document.write( "2 -1 -9 -32
\n" ); document.write( "0 -5 16 74
\n" ); document.write( ":
\n" ); document.write( "R2 -2R1
\n" ); document.write( ":
\n" ); document.write( "2 -6 6 38
\n" ); document.write( "0 5 -15 -70
\n" ); document.write( "0 -5 16 74
\n" ); document.write( ":
\n" ); document.write( "R2 +R3
\n" ); document.write( ":
\n" ); document.write( "2 -6 6 19
\n" ); document.write( "0 5 -15 -70
\n" ); document.write( "0 0 1 4
\n" ); document.write( ":
\n" ); document.write( "R1/2, R2/5
\n" ); document.write( ":
\n" ); document.write( "1 -3 3 19
\n" ); document.write( "0 1 -3 -14
\n" ); document.write( "0 0 1 4
\n" ); document.write( ":
\n" ); document.write( "The above matrix is our row echelon matrix, then
\n" ); document.write( ":
\n" ); document.write( "x -3y +3z = 19
\n" ); document.write( "y -3z = -14
\n" ); document.write( "z = 4
\n" ); document.write( ":
\n" ); document.write( "y -3(4) = -14
\n" ); document.write( "y = -2
\n" ); document.write( ":
\n" ); document.write( "x -3(-2) +3(4) = 19
\n" ); document.write( "x = 1
\n" ); document.write( ":
\n" ); document.write( "**************************************************
\n" ); document.write( "x = 1, y = -2, z = 4
\n" ); document.write( ":
\n" ); document.write( "check the answers
\n" ); document.write( ":
\n" ); document.write( "x - 3y + 3z = 19
\n" ); document.write( ":
\n" ); document.write( "1 -3(-2) +3(4) = 19
\n" ); document.write( "19 = 19
\n" ); document.write( ":
\n" ); document.write( "2x -y - 9z = -32
\n" ); document.write( ":
\n" ); document.write( "2(1) -(-2) -9(4) = -32
\n" ); document.write( "-32 = -32
\n" ); document.write( ":
\n" ); document.write( "-5x +10y +z = -21
\n" ); document.write( ":
\n" ); document.write( "-5(1) +10(-2) +4 = -21
\n" ); document.write( "-21 = -21
\n" ); document.write( ":
\n" ); document.write( "answer checks
\n" ); document.write( "****************************************************\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );