Solving system of equations using the augmented matrix
A system of equations is when we have more than one equation and more than one variable. For example:
They can be solved using the augmented matrix:
We must use elementary row operations to change the coefficient matrix to an identity matrix.
Solve this system of equations using an augmented matrix: 
Augmented matrix :
Then: 
5y=-55, so y=-11
3x-2·(-11)=13
3x+22=13
3x=13-22
3x=-9
x=-3
Solution: (-3,-11)
