Slope-Intercept Equations & Graphing Challenges for 8th Grade

1. A car travels from point A (2, 3) to point B (4, 7). Write the slope-intercept equation of the line that represents the car's path. What is the slope?

• y = 2x - 1; slope = 2

• y = -2x + 4; slope = -2

• y = 3x + 1; slope = 3

• y = x + 5; slope = 1

2. The temperature in a city increases from 30°F at 8 AM (0, 30) to 50°F at 12 PM (4, 50). Write the slope-intercept equation for the temperature change. How would you graph this equation?

• y = 10x + 30

• y = 5x + 30

• y = 5x + 20

• y = 2.5x + 30

3. A bike rental shop charges a flat fee of $10 plus $2 per hour. If the cost at 0 hours is (0, 10) and at 5 hours is (5, 20), write the slope-intercept equation. What is the slope?

• The slope is 0.

• The slope is 2.

• The slope is 5.

• The slope is 10.

Tags

CCSS.8.EE.B.5

4. A student scores 70 points on their first test and 90 points on their second test. If the scores are represented by points (1, 70) and (2, 90), write the slope-intercept equation. How would you graph this?

• y = 20x + 50

• y = 10x + 60

• y = 15x + 55

• y = 25x + 45

5. A plant grows from 5 cm to 15 cm over 4 weeks. If the growth can be represented by points (0, 5) and (4, 15), write the slope-intercept equation. What does the slope represent in this context?

• y = 1.5x + 5; the slope represents the total height after 4 weeks.

• y = 2.5x + 5; the slope represents the growth rate of the plant in cm per week.

• y = 3x + 5; the slope represents the height of the plant.

• y = 2x + 10; the slope represents the initial height of the plant.

6. A store sells 3 shirts for $45 and 5 shirts for $75. If the points are (3, 45) and (5, 75), write the slope-intercept equation. How would you graph this relationship?

• y = 20x + 5

• y = 10x

• y = 5x + 30

• y = 15x

Tags

CCSS.8.EE.B.5

7. A runner completes a 5 km race in 25 minutes and a 10 km race in 50 minutes. If these times are represented by points (5, 25) and (10, 50), write the slope-intercept equation. What does the slope indicate?

• y = 10x

• y = 5x

• y = 2x + 5

• y = 5x + 10

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

8. A phone plan costs $30 per month plus $0.10 per minute. If the cost at 0 minutes is (0, 30) and at 100 minutes is (100, 40), write the slope-intercept equation. How would you graph this?

• C(m) = 30 + 0.05m

• C(m) = 30m + 0.10

• C(m) = 0.10 + 30m

• C(m) = 30 + 0.10m

Tags

CCSS.8.EE.B.5

9. A factory produces 100 toys in 2 hours and 300 toys in 6 hours. If these points are (2, 100) and (6, 300), write the slope-intercept equation. What does the slope represent in terms of production?

• y = 25x + 200

• y = 50x

• y = 100x

• y = 150x + 50

Tags

CCSS.8.EE.B.5