## Monday, September 5, 2022

### Casio fx-991EX Classwiz Tips: Solving a Linear System

Casio fx-991EX Classwiz Tips:  Solving a Linear System

This week I am going to show some things that can be done with the Casio fx-991EX Classwiz.

Solving Linear Systems

The Classwiz can solve linear systems.  To enter the Equation mode:

[MENU], [(-)] for A, 1 for Simul Equation

Up to four variables can be solved for.

One of the nice things of the Classwiz's Equation mode is that the equations as shown as it is written on paper.

For a 3 x 3 system (with coefficients reset to 0):

0x  + 0y + 0z  = 0

0x  + 0y + 0z  = 0

0x  + 0y + 0z  = 0

with a large left bracket symbol, {, to the left of the equations.

Entering negative numbers will change the plus to minuses:  i.e.  5x - 6y instead of 5x + -6y.

Use the equals key [ = ] to enter coefficients and call for solutions.

Example:

- 2x + 11y + 3z = 25

3x + 6y - 8z = 9

10x + 2y + 9z = -3

x = -1231/1479 ≈ -0.8323191346

y = 3086/1479 ≈ 2.086544963

z = 63/493 ≈ 0.1277890467

Eddie

All original content copyright, © 2011-2022.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.

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