Math III Test # 1 Review

This morning in Math III we reviewed for our matrix test, which we will take Thursday, 1/24.  Here are the answers to the review packet.

1) A
2) C
3) A
4) C
5) D
6) B
7) x = 1, y = - 3
8) x = - 1, y = 1
9) A
10) D

For the matrices, I'm not sure how it will come across on the blog.  I will type it in as best as I can and I hope it will look alright.

11)   12     9      15
        8       6      10
        20    15     25

12)   - 10/38     - 6/38
        - 3/38        2/38

13)     14     - 24
          -18    - 2
         34      14

14)     - 1     - 3
         - 3/2    5

15)    5      - 42
        - 18     22
       - 23     26

16)  Can't be done

17)      1   0
           0   1

18)                               Addition      Multiplication
          Commutative         YES               NO
          Associative            YES              NO

19)         x = - 1 , y - - 5