Lesson Plan: Introduction to Linear Equations
Lesson Objectives
- Define linear equations
- Identify components of linear equations
- Represent linear equations using tables, graphs, and equations
- Understand concepts of slope and y-intercept
TEKS Standards
- 7.7A: Represent linear relationships using verbal descriptions, tables, graphs, and equations that simplify to the form y = mx + b.
- 8.4B: Graph proportional relationships, interpreting the unit rate as the slope of the line that models the relationship.
- 8.4C: Use data from a table or graph to determine the rate of change or slope and y-intercept in mathematical and real-world problems.
- 8.5A: Represent linear proportional situations with tables, graphs, and equations in the form of y = kx.
- 8.5B: Represent linear non-proportional situations with tables, graphs, and equations in the form of y = mx + b, where b ≠ 0.
- 8.5I: Write an equation in the form y = mx + b to model a linear relationship between two quantities using verbal, numerical, tabular, and graphical representations.
Prerequisite Skills
- Understanding of variables and algebraic expressions
- Familiarity with the Cartesian coordinate plane
- Basic arithmetic operations (addition, subtraction, multiplication, division)
Key Vocabulary
- Linear equation
- Variable
- Coefficient
- Constant
- Slope
- y-intercept
Warm-up Activity (5 minutes)
Introduce the concept of linear equations by showing real-life examples. Use this slide show:
https://www.media4math.com/library/slideshow/applications-linear-equations
This shows these applications of linear equations:
- Cricket chirps vs. Temperature
- The cost vs. time for renting equipment
- Distance vs. time
Then show this slide show to compare and contrast linear and non-linear graphs:
https://www.media4math.com/library/slideshow/linear-vs-non-linear-graphs
Teach (20 minutes)
Definition and Components of Linear Equations
Define linear equations as equations that form a straight line when graphed. Use this slide show that provides video definitions of linear equations and linear functions:
https://www.media4math.com/library/slideshow/linear-equations-and-functions-definitions
Explain the components: variables, coefficients, and constants.
Here are some additional definitions to review:
- Slope: https://www.media4math.com/library/74617/asset-preview
- y-intercept: https://www.media4math.com/library/74608/asset-preview
- Coefficient: https://www.media4math.com/library/74631/asset-preview
Identifying Linear Equations
Introduce linear equations in standard form and show how this form relates to the slope-intercept form. Use this slide show:
https://www.media4math.com/library/slideshow/linear-equations-standard-and-slope-intercept-form
Representing Linear Equations
- Introduce the three ways to represent linear equations: tables, graphs, and algebraic expressions. Use this slide show of examples of multiple representations of linear equations:
https://www.media4math.com/library/slideshow/multiple-representations-linear-equations
- Demonstrate how to create a table of values and plot points on the coordinate plane. Use this Desmos activity to explore the three representations of linear equations:
https://www.desmos.com/calculator/tfoy9bwov2
- Explain the concept of slope and y-intercept, and their relationship to the equation's form. Use this Desmos activity to explore slope-intercept form:
https://www.media4math.com/library/40088/asset-preview
Review (10 minutes)
Use this slide show to review linear equations and functions, along with an application of slope:
https://www.media4math.com/library/slideshow/linear-equation-review
You can also assign this worksheet, which reviews multiple representations of linear equations and functions:
https://www.media4math.com/library/34317/asset-preview
Assess (5 minutes)
Administer a 10-question quiz to assess students' understanding of linear equations. The quiz should include questions on identifying linear equations, finding components, and representing them in different forms.
Quiz
- Which of the following is a linear equation?
a) y = x^2 + 3
b) 2x + 5y = 10
c) x^3 - y = 0
d) 3x - 2y + 4 = 0
- Identify the coefficient of x in the equation: 4x + 2y = 8.
- What is the y-intercept of the equation y = 2x + 3?
- What is the general form of a linear equation in slope-intercept form?
- What is the general form of a linear equation in standard form?
- Determine if the equation 5x + 2y - 3 = 0 is linear or non-linear.
- Which equation represents this situation: The cost of renting a car is \$25 plus $0.20 per mile.
a) y = 0.2x + 25
b) y = 25x + 0.2
- Identify the variables, coefficients, and constant in the equation: y = -2x + 5.
- Find the slope of the line represented by the equation y = 1/2x + 3.
- Determine if the equation x^2 + y^2 = 25 is a linear equation or not.
Answer Key
- b and d
- 4
- 3
- y = mx + b
- Ax + By = C
- Linear
- a
- Variables: x, y; coefficients: 1, -2; constant: 5
- 1/2
- Not a linear equation
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