1. College Algebra Chapter 2 Functions and Graphs Section 2.4 Linear Equations in Two Variables and Linear Functions

2. Concepts 1. Graph Linear Equations in Two Variables 2. Determine the Slope of a Line 3. Apply the Slope-Intercept Form of a Line 4. Compute Average Rate of Change 5. Solve Equations and Inequalities Graphically

3. Standard Form of the Equation of a Line Ax + By = C where A and B are real numbers and A and B are not both zero.

4. Example 1: Graph the equation and identify the x- and y-intercepts.

5. Example 2: Graph the equation and identify the x- and y-intercepts.

6. Example 3: Graph the equation and identify the x- and y-intercepts.

8. Concepts 1. Graph Linear Equations in Two Variables 2. Determine the Slope of a Line 3. Apply the Slope-Intercept Form of a Line 4. Compute Average Rate of Change 5. Solve Equations and Inequalities Graphically

9. Slope of a Line Slope of a line through and

10. Example 4: Find the slope of a line passing through the given points.

11. Example 5: Find the slope of a line passing through the given points.

13. Example 6: Find the slope of the horizontal line y = 4

14. Example 7: Find the slope of the vertical line x = –3

16. Concepts 1. Graph Linear Equations in Two Variables 2. Determine the Slope of a Line 3. Apply the Slope-Intercept Form of a Line 4. Compute Average Rate of Change 5. Solve Equations and Inequalities Graphically

17. Slope-Intercept Form of a Line y = mx + b slope is m, y-intercept is (0, b)

18. Example 8: Write the equation in slope-intercept form. Use the slope and y-intercept to graph the line.

19. Example 9: Write the equation in slope-intercept form. Use the slope and y-intercept to graph the line.

21. Example 10: Write an equation of the line in slope-intercept form that passes through the point (–2, 3) and has slope 5.

23. Concepts 1. Graph Linear Equations in Two Variables 2. Determine the Slope of a Line 3. Apply the Slope-Intercept Form of a Line 4. Compute Average Rate of Change 5. Solve Equations and Inequalities Graphically

24. Average Rate of Change of a Function If f is defined on the interval [x 1, x 2 ], then the average rate of change of f on the interval [x 1, x 2 ] is the slope of the secant line containing (x 1, f(x 1 )) and (x 2, f(x 2 )). or

25. Examples 11 – 12: Determine the average rate of change 11.From (–1.5, 0) to (0, 2) 12.From (0, 2) to ( 2.5, 1)

28. Concepts 1. Graph Linear Equations in Two Variables 2. Determine the Slope of a Line 3. Apply the Slope-Intercept Form of a Line 4. Compute Average Rate of Change 5. Solve Equations and Inequalities Graphically

29. Example 13: Use the graph to solve the equation

30. Examples 14, 15: Use the graph to solve the inequalities