1. A system of equations can be written in matrix form. Determine the coefficient, variable, and constant matrices. Write the matrix equation. A • X B = Answer: Example 8-1a

2. Why does it work??? Example 8-1a

3. Write a matrix equation for the system of equations. Answer: Example 8-1b

4. Use the matrix equation to solve the system of equations. B A X A-1 B A-1 A = X  A-1 I = X B  A-1 = X B Example 8-1b

5. A-1 = X B

6. Use a matrix equation to solve the system of equations. A  X = B The matrix equation is Example 8-3a

7. A  X = B = A-1 = X B Answer: The solution is (5, –4). Example 8-3b

8. Use a matrix equation to solve the system of equations. The matrix equation is when Example 8-4a

9. The determinant of the coefficient matrix is 0,so A–1 does not exist. A-1 = X B Example 8-4b

10. Graph the system of equations. Since the lines are parallel, thissystem has no solution. Example 8-4c