Matrix Multiplication

I am coming do this blog now, so I can go finish all of your study guidess..

--To multiply matrices
(a)(b)x(b)(c)
The inner numbers have to match

--The resulting matrix will be a(c)

Example 1:
Find each matrix product, if it is defined.
[4 3 [5 = [23
-1-2] 1] -7]
2x2 2x1
4(5)+3(1)=23
-1(5)+-2(1)=-7

Example 2:
Find each matrix product, if it is defined.
[-6 [-1 12 = Not Defined
0] 0 -4]
2x1 2x2
*inner numbers do not match, so it is not defined

Example 3:
Find each matrix product, if it is defined.
[1 -5 [4 -4 = [4 -9
2 3] 0 1] 8 -5]
2x2 2x2
1(4)+-5(0)=4
1(-4)+-5(1)=-9
2(4)+3(0)=8
2(-4)+3(1)=-5

Example 4:
Find each matrix product, if it is defined.
[-2 3 [0 3 = [-18 9
4 2] -6 5] -12 32]
2x2 2x2
-2(0)+3(-6)=-18
-2(3)+3(5)=9
4(0)+2(-6)=-12
4(3)+4(5)=32

Example 5:
Find each matrix product, if it is defined.
[8 -10 [-2 = Not Defined
0 3 -9
-6 4] 1]
3x2 3x1
*inner number do not match, so it is not defined

***Again, I am sorry for the messed up matrices. I haven't figured out how to fix them yet.