Practice!

Sample Problem

Solve this system using an inverse matrix.

x=

y=

z=

Solution

Write the system in the matrix form AX=B

Adjoin matrix A with the identity matrix and use Gauss-Jordan elimination to find the inverse of A (A-1):

E3=E3-E2

Switch E2 withE3

E3=E3-E2

E3=E3/2

E1=E1-E3

Multiply B by A-1 on the left to obtain the solution:

X=A-1B

The solution of the system is x=2, y=6, and z=-1