# Activities

• • • ##### Subject Area

• Math: Algebra I: Systems of Linear Equations

• ##### Author 9-12

90 Minutes

• ##### Device
• TI-89 / TI-89 Titanium
• TI-92 Plus / Voyage™ 200
• ##### Other Materials
This is Activity 3 from the EXPLORATIONS Book:
Discovering Math on the Voyage 200.
• ##### Report an Issue

Solving Systems of Equations

#### Activity Overview

Students explore three different methods for solving linear systems on either the TI-89 Titanium, TI-89, TI-92 Plus, or the Voyage 200.

#### Before the Activity

• See the attached PDF file for detailed instructions for this activity
• Print pages 15 - 22 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.
Solving Systems with the Elimination-by-Addition Method:

• Study both equations with two unknowns x and y
• Maniplulate equations algebraically so that one variable is eliminated when the equations are added together

• Write the solution for one variable and solve the equation for the other variable

• Solving Systems with the Substitution Method:
• Study three equations with three unknowns x, y, and z
• Store all three equations on the calculator
• Write the first equation for z in terms of x and y
• Substitute the new equation of z into the two other equations
• Solve for x and y by elimination method
• Enter values of x and y and solve for z

• Solving Systems by the Simultaneous-Equations method:
• Enter the coefficients as a set (matrix) in brackets
• Enter the set of result constants (vector) also in brackets
• Solve equations using matrices
• #### After the Activity

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary