1. Lesson 11.5 Using Intercepts
Essential Question: How do you find the x- and y-intercept of a linear equation?

2. Before we start…
What do you notice about the graph of this line?

3. When graphing a line…
The fact is that you only need 2 points to determine a line.
Two convenient points to use are the points where the graph crosses the axes.

4. What is an intercept?
Crosses the y -axis.
Crosses the x -axis.

5. What are the intercepts?
y-Intercept – where the graph intersects the y-axis
It’s the y-coordinate of the intersecting point. (0, y)
x-Intercept – where the graph intersects the x-axis
It’s the x-coordinate of the intersecting point. (x, 0)
ORDERED PAIRS, (x, y)

6. How can I find intercepts?
To find the x-intercept
Let y = 0 and solve the equation for x.
To find the y-intercept
Let x = 0 and solve the equation for y.

7. Find the x and y-intercepts of the graph.

8. Find the x and y-intercepts of the graph.
𝑦= 1 2 𝑥−5

9. Find the x and y-intercepts of the graph.

10. Find the x and y-intercepts of the graph.
𝑦=2𝑥−10

11. Find the x and y-intercepts of the graph.

12. Why do I need intercepts?
If you are given the x and y-intercepts, it is one way to graph a line.
If you are given an equation in standard form, you can use intercepts to graph.

13. Graph the line with an x-intercept of -3 and a y-intercept of 2.

14. Graph the line with an x-intercept of 6 and a y-intercept of -10.

15. What is standard form?
A, B and C are all integers and A and B are not equal to 0.

16. How can I graph an equation in standard form?
Verify the equation is in standard form Ax + By = C
Find the x-intercept
Find the y-intercept
Plot the intercepts on your graph.
Draw a line to connect the dots.

20. Fitness Deena runs and walks with her dog on a trail that is 8 miles long. She can run 4 miles per hour and walk 2 miles per hour. Graph the equation 4𝑥+2𝑦=8, where x is the number of hours she runs and y is the number of hours she walks. What do the intercepts represent?

21. Snacks James spends $24 for cookies and ice cream
Snacks James spends $24 for cookies and ice cream. Cookies cost $3 a box and ice cream costs $4 a carton. Graph the equation 3𝑥+4𝑦=24, where x is the number of cookie boxes and y is the number of ice-cream cartons. What do the intercepts represent?

22. How do you find the x- and y-intercept of a linear equation?

23. Ticket Out the Door
Find the x and y-intercepts of the equation. 5𝑥−2𝑦=10