Matrices are rectangular
arrays of elements.
The dimension of a matrix is the number of
rows by the number of columns. 

Adding Matrices
 matrices must be of the same dimension to be added.
Add:
First Enter the Matrices (one at a time): 
Step 1: Go to Matrix
(above the x^{1 }key)
If dimensions appear next to the names of the matrices,
such as 3x3, a matrix is already stored in the calculator. You
may save it by moving to a new name, or overwrite it.

Step 2: Arrow to the right to
EDIT
to allow for
entering the
matrix.

Step 3: Type in the dimensions (size) of your
matrix
and enter the elements (press ENTER).

Step 4: Repeat this process for
the second matrix
. 
Step 5: Arrow to the right to
EDIT
and choose a
new name.

Step 6: Type in the dimensions (size) of
your matrix
and enter the elements (press ENTER).

Now, add:
Step 7: Return to the home
screen. Go to Matrix
to
get the names of the
matrices for adding.

The answer to the addition, as seen
on the calculator screen,
is =


Multiplying Matrices for multiplication to
occur, the dimensions of the matrices must be related in
the following manner: m x n times n x r
yields m x r
Multiply:
First Enter the Matrices (one at a time) as shown above: 
Step 1: Once the matrices are entered, you should
see their dimensions in residence when you go to Matrix
(above the x^{1 }key)

Step 2: Return to the home
screen. Go to Matrix
to
get the names of the
matrices for multiplying.

The product, as seen
on the calculator screen, is =

Using Matrices to Solve Systems of Equations:
1. (using the inverse coefficient matrix)
Write this system as a matrix equation and solve: 3x + 5y = 7 and 6x  y =
8 
Step 1: Line up the x, y and
constant values.
3x + 5y = 7
6x 
y = 8

Step 2: Write as equivalent
matrices.

Step 3: Rewrite to separate out
the variables.

Step 4: Enter the two numerical matrices in the
calculator.

Step 5: The solution is obtained by multiplying both
sides of the equation by the inverse of the matrix which is multiplied
times
the variables.

Step 6: Go to the home screen and enter the right side of
the previous equation.


The answer to the system,
as seen on the calculator screen,
is x = 1 and y = 2.

Note: If the determinant of a matrix is zero, the matrix does not have an inverse. Thus, a single point, (x,y), solution cannot be found.
