Solving Simultaneous Equations Using Row Reduction Operations on The Augmented Matrix
We can solve a system of linear simultaneous equations by forming the augmented matrix and using elementary row operations to reduce to upper triangular form. The solutions can then be found by back substitution.
Example: Solve the system of equations
The augmented matrix is
We can interchange rows 1 and 2, to make the entry in the upper left hand corner 1.
Subtract twice the first row from the second row, and three times the first row from the second row.
Subtract seven times the second row from the third row.
From the third eow,
From the second row,
From the first row,