What is Gauss-Jordan elimination?

1 Answer
Oct 30, 2014

Gauss-Jordan elimination is a technique for solving a system of linear equations using matrices and three row operations:

  1. Switch rows
  2. Multiply a row by a constant
  3. Add a multiple of a row to another

Let us solve the following system of linear equations.

{(3x+y=7),(x+2y=-1):}

by turning the system into the following matrix.

Rightarrow ((3" "1" "" "7),(1" "2" "-1))

by switching Row 1 and Row 2,

Rightarrow((1" "2" "-1),(3" "1" "" "7))

by multiplying Row 1 by -3 and add it to Row 2,

Rightarrow((1" "" "2" "-1),(0" "-5" "10))

by multiplying Row 2 by -1/5,

Rightarrow((1" "2" "-1),(0" "1" "-2))

by multiplying Row 2 by -2 and add it to Row 1,

Rightarrow((1" "0" "" "3),(0" "1" "-2))

by turning back into a system of equations,

Rightarrow{(x=3),(y=-2):},

which is the solution of the original system.


I hope that this was helpful.