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.

Additional Learning Objective(s):

The student will write linear equations in standard form.

 Preparation Information 

Total Duration:

31 to 60 Minutes

Materials and Resources:

Technology Resources Needed:

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: 

Before:

The teacher will have the bell ringer on the interactive whiteboard as the students enter the room. The document, Bell Ringer Elimination, is located in the attachment section. The answers are on the second page. The student will write the answers in their notebooks. The teacher will call on students to answer the definitions for elimination and solution. The teacher will select students to write the lines in standard form.

 

During:

  1. The teacher will show the video for solving by elimination. (https://www.youtube.com/watch?v=8kRG7jlBMAY)
  2. The teacher can post the two PowerPoint presentations in Google Classroom. The students will be able to use the presentations with the exercises in their groups and follow along with the teacher as the lesson is presented.
  3. The teacher will open the PowerPoint presentation, “Systems Add or Minus”. 
  4. The teacher will go slowly through the examples. While explaining the examples, the teacher can do another informal assessment. The teacher does not continue the slides until all students are ready.
  5. After “Systems Add or Minus”, the teacher will open the presentation, “Systems Multiplication”. 
  6. The teacher will explain each example thoroughly. The presentation has informal assessments in the slides.
  7. The teacher will hand out the worksheet from the website, Kuta Software. (https://cdn.kutasoftware.com/Worksheets/Alg1/Systems%20of%20Equations%20Elimination.pdf)
  8. The teacher will put students in groups of four students. The students can use their devices to watch the presentations from Google Classroom to assist in answering the questions on the worksheet. The groups can have a peer-tutor to help intervention students. The worksheet will be an informal assessment tool.
  9. The teacher will do a one-on-one intervention with the groups.
  10. The teacher will ask students to work problems on the interactive whiteboard.

After:

The teacher will hand out the exit slip, “Exit Elimination”. The students will turn in the exit slip as they leave the classroom. The teacher will use the exit slip as the formal assessment. 



Attachments:
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  Assessment  

Assessment Strategies

Informal Assessments:

The teacher will check for understanding of the standard form of a line during the bell ringer.

The teacher will check for understanding during both PowerPoint presentations.

The teacher will use the worksheet from Kuta Software to assess student understanding of solving systems of equations using elimination. 

Formal Assessment:

The teacher will use the exit slip and an overall summation of the lesson in its entirety to formally assess students. 

Acceleration:

The teacher will assign the worksheet, "ACC Elimination". The worksheet has more challenging coefficients and multiplication with both linear equations. The answers are on page two.

Intervention:

The teacher will have copies of the PowerPoint slides for the students. The teacher will allow students to be in groups with a peer-tutor. The teacher will monitor and assist students one-on-one.


View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.