1. Slope and introduction to slope-intercept
Unit 4 Linear Functions
Slope and introduction to slope-intercept

2. Warm-Up
y varies directly with x. Write the direct variation equation if y = 15 when x = 3.
Solve the equations for y:
a) b)

3. Homework 4.5 Check Yes, yes 2. no, no 3. yes, yes
4. no, no 5. no, no 6. yes, yes
7. X = y = x = 12
10. X = y = y = 6.4

4. Homework 4.6 Check 1 2. ½ 3. –3/2 4. ¼ 5. -3 6. -4/3 7. 2 8. -3 9. 2/7
½ 3. –3/2
4. ¼ /3 /7
10. 7/ quarts feet
cups

5. Recall from yesterday!

6. An equation whose graph is a line is a Linear Equation
An equation whose graph is a line is a Linear Equation. Examples of Linear Equations:

7. The y-intercept is the y-coordinate of the point where a line crosses the y-axis. Y-intercept: SLOPE: (rate of change)

11. Write an equation of the line with Step 1: Write the slope-intercept form equation Step 2: Substitute the given slope and y-intercept from the problem

12. Write an equation of the line with

13. Step 1: Find two points on the graph
Step 1: Find two points on the graph. Step 2: Find the slope of those points Step 3: Determine the y-intercept Step 4: Write the equation of the line

14. Write an equation of the line:

15. Write the equation of the line:

16. Graphing a line given the equation
Step 1: Graph the y-intercept. Step 2: Using the slope, graph a second point on the line. Step 3: Draw a line through the two points

19. The base pay of a water-delivery person is $210 per week
The base pay of a water-delivery person is $210 per week. He also earns 20% commission on any sale he makes. The equation t= s relates total earnings t to sales s. What is the slope of the equation? What is the y-intercept?

20. Homework
4.6