Lesson Plan: Graphing Linear Equations

Lesson Objectives:

• Plot points on the coordinate plane
• Identify the slope and y-intercept of a linear equation
• Graph linear equations using the slope-intercept form
• Interpret the meaning of slope and y-intercept in real-life situations

Common Core Standards:

• 8.EE.B.5: Graph proportional relationships, interpreting the unit rate as the slope of the graph.
• 8.EE.B.6: Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane.

Prerequisite Skills:

• Plotting points on the coordinate plane
• Understanding of slope and y-intercept concepts

Key Vocabulary:

• Coordinate plane
• Ordered pair
• Slope
• y-intercept
• Slope-intercept form

Warm-up Activity (5 minutes)

For students that need to review graphing points on the coordinate plane review the first example from this video:

https://www.media4math.com/library/39514/asset-preview

Engage students by asking them to plot the following points on a coordinate plane:

(1, 2)

(2, 4)

(3, 6).

Use this Desmos activity to graph the points and ask students to notice any patterns.

https://www.desmos.com/calculator/cq834lfyfp

Teach (20 minutes)

Definitions

Use the following video definitions to define key terms:

Examples

Demonstrate how to identify the slope and y-intercept from a given linear equation.

Assess (10 minutes)

Administer a 10-question quiz to assess students' understanding of graphing linear equations. The quiz should include questions on plotting points, identifying slope and y-intercept, graphing linear equations, and interpreting slope and y-intercept in real-life situations.

Quiz

1. Plot the points (1, 2), (-2, -1), and (3, 4) on the coordinate plane.
2. Identify the slope and y-intercept of the equation y = 2x + 3.
3. Graph the equation y = -1/2x + 4 on the coordinate plane.
4. If the slope of a linear equation is 3 and the y-intercept is -2, what is the equation?
5. Interpret the meaning of the slope and y-intercept in the equation y = 0.5x + 10. You save fifty cents a day in a piggy bank that already has an amount of money in it.
6. A line passes through the origin and through (4, 9). What is its equation?
7. Determine if the point (3, -1) lies on the line represented by the equation y = 2x - 5.
8. Graph the equation 3y = 6x - 9 on the coordinate plane.
9. Explain the relationship between the slope of a line and its steepness.
10. This equation represents a car slowing down every second at a constant speed (in miles per hour): y = -5x +50. What is the car's initial speed? What does the slope represent?