# ALEX Lesson Plan

## Systems of Equations Part 3 -- Solving by Elimination

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This lesson provided by:
 Author: Morgan Boyd Organization: Retirement
General Lesson Information
 Lesson Plan ID: 35662 Title: Systems of Equations Part 3 -- Solving by Elimination Overview/Annotation: This lesson will be completed in one class period. This lesson, the third in the series, will focus on another way of solving linear systems, the elimination method. When using this method, the students will multiply one or both of equations to make one of the variables equal. Afterward, the students will add the equations to eliminate the variable.  This lesson results from the ALEX Resource Gap Project.
Associated Standards and Objectives
Content Standard(s):
 Mathematics MA2015 (2016) Grade: 8 10 ) Analyze and solve pairs of simultaneous linear equations. [8-EE8] a. Understand that solutions to a system of two linear equations in two variables correspond to points of intersections of their graphs because points of intersection satisfy both equations simultaneously. [8-EE8a] b. Solve systems of two linear equations in two variables algebraically, and estimate solutions by graphing the equations. Solve simple cases by inspection. [8-EE8b] Example: 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously be 5 and 6. c. Solve real-world and mathematical problems leading to two linear equations in two variables. [8-EE8c] Example: Given coordinates for two pairs of points, determine whether the line through the first pair of points intersects the line through the second pair. NAEP Framework NAEP Statement:: 8A4a: Solve linear equations or inequalities (e.g., ax + b = c or ax + b = cx + d or ax + b > c). NAEP Statement:: 8A4c: Analyze situations or solve problems using linear equations and inequalities with rational coefficients symbolically or graphically (e.g., ax + b = c or ax + b = cx + d). Alabama Alternate Achievement Standards AAS Standard: M.AAS.8.10 - Identify the labeled point of intersection on graphs of two linear equations as a solution for both equations.

Local/National Standards:

Primary Learning Objective(s):

The student will solve systems of equations using the elimination method.

The student will write linear equations in standard form.

Preparation Information
 Total Duration: 31 to 60 Minutes Materials and Resources: PencilsNotebookiPad, Chromebook, or Mac Book for each student for Google Classroomhttps://www.youtube.com/watch?v=8kRG7jlBMAYBell Ringer Elimination (attachment section -- place on interactive whiteboard as students enter the classroom)Exit Elimination (attachment section -- make copies for all students)ACC Elimination (attachment section -- make copies for accelerated students)PowerPoint Presentations:Systems Add or Minus (attachment section)Systems by Multiplication (attachment section)Worksheet: https://cdn.kutasoftware.com/Worksheets/Alg1/Systems%20of%20Equations%20Elimination.pdf (make copies for all students) Technology Resources Needed: Desktop computer with ability to project to interactive whiteboardWebsite: https://cdn.kutasoftware.com/Worksheets/Alg1/Systems%20of%20Equations%20Elimination.pdf Background/Preparation: Teacher:Solving systems of linear equations by graphing and solving systems of linear equations by substitution should have been taught prior to teaching this lesson. This lesson will be taught in one class period. The teacher will need to preview the PowerPoint presentations.Student:The student needs to know how to write linear equations in standard form, Ax + By = C. The student will need to know the definitions of the following terms: coefficients, eliminate, opposites, and solution. The terms and definitions will be included on the bell ringer.
Procedures/Activities: