Unit 4, Lesson 16
Solving Systems by Elimination (Part 3)
Integrated Math 1
Preparation
Lesson Narrative
This is the last lesson in a series of three lessons on solving systems of equations by elimination. Two new ideas are introduced here.
The first new idea is that we can multiply one or both equations in the system by a factor to make it possible to eliminate a variable.
The second new idea is that whenever we multiply equations in a system by a factor, add or subtract the equations, or otherwise write an equivalent equation, we are essentially creating an equivalent system that would help us get closer to finding the solution of the original system.
As they work to process and articulate these key ideas, students practice constructing logical arguments (MP3).
- Recognize that multiplying an equation by a factor creates an equivalent equation whose graph is the same as that of the original equation.
- Solve systems of equations by multiplying one or both equations by a factor and then adding or subtracting the equations to eliminate a variable.
- Understand that solving a system by elimination or by substitution entails creating one or more equivalent systems that would enable us to solve the original one.