1. 3.7 Equations of Lines in the Coordinate Plane
The slope m of a line is the ratio `of the vertical change (rise) to the horizontal change (run) between any two points.

2. Find Slopes of Lines
Find the slope of line a and line d.

3. Slopes of Lines in Coordinate Planes
Negative slope – falls from left to right.
Positive slope – rises from left to right.
Zero slope (slope of 0) – horizontal line
Undefined slope – vertical line

4. Forms of Linear Equations
The slope intercept form of an equation of a nonvertical line is y = mx + b, where m is the slope and b is the y-intercept.
The point-slope form of an equation of a nonvertical line is y – y1 = m (x – x1), where m is the slope and (x1 , y1) is a point on the line.

5. Graphing Lines
What is the graph of
Starting point (0 , 1)

6. Graphing Lines What is the graph of y – 3 = -2 (x + 3)
Starting point (-3 , 3)

7. Writing Equations of Lines
What is an equation of the line with the slope 3 and y – intercept -5?
y = mx + b
y = 3x – 5

8. Writing Equations of Lines
What is the equation of the line through point (-1 , 5) with slope 2?
y – y1 = m (x – x1)

9. Using Two Points to Write an Equation
What is an equation of the line with points (-2 , -1) and (3 , 5)?

10. Writing Equations of Horizontal and Vertical Lines
What are the equations for the horizontal and vertical lines through (2 , 4)?
y = 4 – horizontal line
x = 2 – vertical line

11. More Practice!!!!!
Homework – textbook p. 194 # 8 – 36 even.