How do you make more matrices on ti 84?

Answer 1

First, enter each coefficient of each variable into a matrix. You can do this by press [2nd][x⁻¹](Matrix) > Edit and choosing a matrix from the list. I'll use [A] in this example.

Set its dimensions to be 3×4, and enter each member as such:

[[ 1 2 5 -1]

[ 2 -1 1 2]

[ 3 4 -4 14]]

When you have all those entered in, exit back to the home screen.

In order to find the solutions to the system, you'll have to change the matrix to reduced row-echelon form. Fortunately, the calculator has an option to do that for you.

Select [2nd][x⁻¹](Matrix) > Math > B:rref(. Now, enter in [A] by going to [2nd][x⁻¹](Matrix) > 1:[A] and press [Enter]. You can then use the [Math] > 1:►Frac command to make the matrix a bit more readable. I get the following matrix:

[[ 1 0 0 2 ]

[ 0 1 0 4/7 ]

[ 0 0 1 -10/7 ]]

Therefore x = 2, y = 4/7, and z = -10/7.