Course: Algebra II / Elementary Algebra
Topic: Linear Systems
Subtopic: 2x2 Systems of Equations I - Graphically
Overview
When we studied lines, the equation was a single equation in two variables such as y=-2x+5. Today's lesson involves solving a system of linear equations meaning that there are two or more equations to be solved simultaneously (at the same time). A 2x2 (read "two by two") system is two equations in two variables, a 3x3 system is three equations in three variables, etc. The solution to a 2x2 system is a point that lies at the intersection of the two lines in the system. So our goal today is to graph the lines in the system, find their intersection point, and that (x,y) is the solution to the system.
Objectives
By the end of this topic you should know and be prepared to be tested on:
- 5.1.1 Know what it means to be a solution to a system of equations (algebraically and graphically)
- 5.1.2 Be able to check if given values are actually a solution to a given system
- 5.1.3 By observing a graph of a linear system, be able to identify if the system has no solution, one solution, or an infinite number of solutions
- 5.1.4 Solve a 2x2 linear system of equations by graphing manually
- 5.1.5 Solve a 2x2 linear system of equations by graphing electronically and using the grapher's intersection feature
Terminology
Define: linear, system, linear system of equations, consistent system, inconsistent system, dependent system
Text Notes
Text:
Intro & Inter Algebra for CS 3ed by Blitzer, sect. 4.1
- pg 264 Useful chart shows how to determine the number of solutions a system has.