1. Objective The student will be able to:
find the x- and y-intercepts of linear equations.

2. What does it mean to INTERCEPT a pass in football?
The path of the defender crosses the path of the thrown football.
In algebra, what are x- and y-intercepts?

3. What are the x- and y-intercepts?
The x-intercept is where the graph crosses the x-axis.
The y-coordinate is always 0.
The y-intercept is where the graph crosses the y-axis.
The x-coordinate is always 0.
(2, 0)
(0, 6)

4. Find the x- and y-intercepts. 1. x - 2y = 12
x-intercept: Plug in 0 for y.
x - 2(0) = 12
x = 12; (12, 0)
y-intercept: Plug in 0 for x.
0 - 2y = 12
y = -6; (0, -6)

5. Find the x- and y-intercepts. 2. -3x + 5y = 9
x-intercept: Plug in 0 for y.
-3x - 5(0) = 9
-3x = 9
x = -3; (-3, 0)
y-intercept: Plug in 0 for x.
-3(0) + 5y = 9
5y = 9
y = ; (0, )

6. Find the x- and y-intercepts. 3. y = 7 ***Special case***
x-intercept: Plug in 0 for y.
Does 0 = 7?
No! There is no x-intercept. None
What type of lines have no x-intercept?
Horizontal!
Remember VUXHOY?
Horizontal lines…y = 7…y-int = (0, 7)

7. What is the x-intercept of 3x – 4y = 24?
(3, 0)
(8, 0)
(0, -4)
(0, -6) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

8. What is the y-intercept of -x + 2y = 8?
(-1, 0)
(-8, 0)
(0, 2)
(0, 4) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

9. What is the y-intercept of x = 3?
(3, 0)
(-3, 0)
(0, 3)
None 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

10. Find the x- and y-intercepts of 2x + 3y = 6 using the graphing calculator.
Before using the calculator, you must solve the equation for y first.
3y = -2x + 6
y =
Type the equation in the Graph menu and graph it.

11. Your graph should look like this
Your graph should look like this. It may vary depending on your window size.
Press F5 (G-Solv) and
select F1 (Root) to determine the x-intercept.
The x-intercept is (3, 0)

12. Now find the y-intercept!
Press F4 (Y-ICPT) for the y-intercept.
y-intercept = (0, 2)

13. X-intercept Slope Y-intercept
Word Bank:
X-intercept Slope Y-intercept
The graph below shows a plan as it makes its descent into DFW airport.
At what height does the airplane begin its descent?
What is the term for this point?
When does it land?
How fast is it descending?

14. The graph below shows the value of a van over time
The graph below shows the value of a van over time. What is the meaning of the slope?
The van was purchased for $16,000
The value of the van increases by $1,600 a year.
The value of the van decreases by $1,600 per year.
The van has no value after 10 years.

15. The graph below shows the value of a van over time
The graph below shows the value of a van over time. What is the meaning of the x-intercept?
The van was purchased for $16,000
The value of the van increases by $1,600 a year.
The value of the van decreases by $1,600 per year.
The van has no value after 10 years.

16. The graph below shows the value of a van over time
The graph below shows the value of a van over time. What is the meaning of the y-intercept?
The van was purchased for $16,000
The value of the van increases by $1,600 a year.
The value of the van decreases by $1,600 per year.
The van has no value after 10 years.

17. The graph below shows the number of popcorn balls and caramel apples needed to raise exactly $200 for the math club.
What is the meaning of the x-intercept?
50 popcorn balls will raise $200
40 caramel apples will raise $200.
Popcorn balls cost $4 each
Caramel apples cost $5 each

19. Example 2: 900 30 month Spends 30 month Starts 900
Will run out of money month
-30
Y = -30x + 900
Y = -50x + 900

20. Whiteboards