1. Warm Up #6 1. Let a = 4, b = – 5, c = – 2, and d = 7. Find ad – bc.
(4)(7) – (-5)(-2)
28 – 10 18
2. Solve the linear system.
2x – 3y = 4
–x – 2y = –9
2x – 3(2) = 4
2( )
2x – 3y = 4
–2x – 4y = –18
2x – 6 = 4
2x = 10
x = 5
-7y = -14
(5 , 2)
y = 2

3. = 1(3*6 – 2*4) – 1(-1*6 – 0*4)+ 2(-1*2 – 0*3)
1(18 – 8) – 1(-6) +2(-2) = – 4 = 12

4. EXAMPLE 1
Evaluate determinants
Evaluate the determinant of the matrix. a. 5 4 3 1 b. 2 3 4 1 –
SOLUTION

9. Solve a system of equations in three variables using the graphing calculator
APPS  PlySmlt2  #2 
Enter the equation in augmented matrix form

10. Use the PolySmlt2 application on your calculator to solve:
Gives:
X1=3-2x3
Means:
INFINITE # of Solutions
X = -3
Y = 4
Z = 1
No solution