1. Five-Minute Check (over Lesson 1–3) Mathematical Practices Then/Now
New Vocabulary
Key Concept: Slope-Intercept Form
Example 1: Write an Equation in Slope-Intercept Form
Key Concept: Slope-Intercept Form
Example 2: Write an Equation Given Slope and One Point
Example 3: Write an Equation Given Two Points
Key Concept: Parallel and Perpendicular Lines
Example 4: Write an Equation of a Parallel or Perpendicular Line
Lesson Menu

2. Find the rate of change for the data.
A. –22 mi/gal
B. mi/gal
C. mi/gal
D. 22 mi/gal
5-Minute Check 1

3. Find the slope of the line that passes through points (2. 3, 9
Find the slope of the line that passes through points (2.3, 9.5) and (3.8, 20).
A. –7 B.
C. 7 D.
5-Minute Check 2

4. Find the slope of the line that passes through points (3, 5) and (–6, 5).
B. 0
C. 1
D. 3
5-Minute Check 3

5. Determine the rate of change of the graph.B. C.
D. 3
5-Minute Check 4

6. A. 72 cm
B. 108 cm
C. 432 cm
D. 648 cm
5-Minute Check 5

7. Mathematical Practices 2 Reason abstractly and quantitatively.
Content Standards
A.SSE.1.b Interpret complicated expressions by viewing one or more of their parts as a single entity.
A.CED.2 Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales. MP

8. You determined slopes of lines.
Write an equation of a line given the slope and a point on the line.
Write an equation of a line parallel or perpendicular to a given line.
Then/Now

9. slope-intercept form point-slope form parallel perpendicular
Vocabulary

10. Concept 1

11. • Write an equation in slope-intercept form for the line.
Step 1 Find the slope.
Slope formula
(x1, y1) = (–1, 4), (x2, y2) = (2, 3)
Simplify.
Example 1

12. Step 2 Use the slope and a point to find the y-intercept.
Write an Equation in Slope-Intercept Form
Step 2 Use the slope and a point to find the y-intercept.
Slope-intercept form
Simplify.
The y-intercept is
Example 1

13. Step 3 Substitute the values into the slope-intercept equation.
Write an Equation in Slope-Intercept Form
Step 3 Substitute the values into the slope-intercept equation.
Slope-intercept form
Example 1

14. Write an equation in slope-intercept form for the line.B. C. D.
Example 1

15. Concept 2

16. Point-slope form Simplify. Write an Equation Given Slope and One Point
Example 2

17. Subtract 2 from each side.
Write an Equation Given Slope and One Point
Subtract 2 from each side.
Answer:
Example 2

18. A. B. C. D.
Example 2

19. What is an equation of the line through (2, –3) and (–3, 7)?
Write an Equation Given Two Points
What is an equation of the line through (2, –3) and (–3, 7)? A B C D
Read the Test Item
You are given the coordinates of two points on the line.
Example 3

20. Step 1 Find the slope of the line.
Write an Equation Given Two Points
Solve the Test Item
Step 1 Find the slope of the line.
Slope formula
(x1, y1) = (2, –3), (x2,y2) = (–3, 7)
Simplify.
The slope is –2. That eliminates choices B and C.
Example 3

21. Step 2 Write an equation. Use either ordered pair for (x1, y1).
Write an Equation Given Two Points
Step 2 Write an equation. Use either ordered pair for (x1, y1).
Point-slope form
m = –2; (x1, y1) = (2, –3)
Simplify.
Subtract 3 from each side.
Answer: D
Example 3

22. Which is an equation of the line that passes through (2, 5) and (–1, 3)?B. C. D.
Example 3

23. Concept

24. Write an Equation of a Parallel or Perpendicular Line
Write an equation in slope-intercept form for the line that passes through (3, –2) and is perpendicular to the line whose equation is y = –5x + 1.
Example 4

25. Distributive Property
Write an Equation of a Parallel or Perpendicular Line
Point-slope form
Distributive Property
Subtract 2 from each side.
Answer:
Example 4

26. A. B. C. D.
Example 4