1. Warm-Up
BC 3. |A|

2. Quiz Questions??

3. Solving Matrix Equations
Suppose AX = B
How do you solve for x?
Ex 4x=20

4. ***We cannot divide matrices, but we can multiply by the inverse***
***A-1 has to be first!!!!!
A-1
AX = B
A-1
IX = A-1B
X = A-1B

5. Ex. Solve a Matrix Equation for X
Remember:
X=A-1B
Step 1: find A-1
A-1=

6. We have… Step 2: Multiply both sides of the equation
by A-1 (in front!)
***You can check the
Solution by multiply
AX to see if you get B

7. Ex. Solve a Matrix Equation for X
Remember:
X=A-1B
Step 1: find A-1
A-1=

8. We have… Step 2: Multiply both sides of the equation
by A-1 (in front!)
***You can check the
Solution by multiply
AX to see if you get B

9. You Try!!!

10. HOMEWORK