Texas Instruments TI-89 Titanium Manual

Like the solve function, you can use the matrix function to solve
for a system of equations. For example:
3x-5y=4 and -2x+5y=6
• Step 1 Press 2
nd
5(MATH), 4(Matrix), and then 5(simult).
• Step 2 Enter the coefficients as a matrix and the results as a
constant column matrix as so: simult([3,-5;-2,5],[4;6])
• Step 3 Press enter. The value for x on top and y on bottom.
Using the same equations, you can solve for x and y using the rref
function.
• Step 1 Press 2
nd
5(MATH), 4(Matrix), and then 4(rref).
• Step 2 Enter an augmented matrix, this contains the variables x,
y, and c where c is the constant. It should look like this: rref([3,-
5,4;-2,5,6])
• Step 3 Press enter; x is on top, y is on bottom.

Texas Instruments TI-89 Titanium Specifications

General

Display Type	LCD
Display Resolution	160 x 100 pixels
CPU	Motorola 68000
CPU Speed	16 MHz
RAM	256 KB
Flash ROM	2.7 MB
Programming Language	TI-BASIC, Assembly
Power Source	4 AAA batteries
Connectivity	I/O port
Dimensions	7.5 x 3.5 x 1 inches