Writing Linear Equations from Situations and Graphs

Mr. Roush introduces 8th-grade students to writing linear equations from situations and graphs. The lesson covers how to model linear relationships using equations in the form y = mx + b, where m is the slope and b is the y-intercept. Students learn to write equations from both graphs and verbal descriptions, using examples like Greta's studio costs and a video club membership. The video also includes practice problems to reinforce the concepts of slope, y-intercept, and linear relationships.

What is the essential question for this module?

• How do you calculate the volume of a cylinder?

• How do you write an equation to model a linear relationship given a graph or a description?

• How do you solve quadratic equations?

• How do you find the area of a circle?

What is the membership fee Greta pays each month?

• $10

• $25

• $15

• $20

If Greta uses the equipment for 10 hours, what will be her total cost for the month?

• $60

• $45

• $75

• $30

What is the slope in the equation y = 3x + 15?

• 3

• 15

• 0

• 1

Where does the graph cross the y-axis in the example provided?

• At 5

• At 0

• At 8

• At 10

What is the slope of the line in the graph example?

• 0.5

• 1.25

• 2

• 3

What is the y-intercept in the equation y = 4/3x - 50?

• 50

• -50

• 4/3

• 0

What is the slope in the equation y = 4/3x - 50?

• 0

• 50

• -50

• 4/3

If a sales associate earns a $500 hiring bonus and $250 per week, what is the total earnings after 12 weeks?

• $3000

• $4500

• $4000

• $3500

How many days will it take to harvest 75 acres of wheat if 12 acres are harvested per day?

• 6.25 days

• 8 days

• 5.5 days

• 7 days