1. To write equations of lines in the point-slope form.

2. Essential question 
What are the different ways to write the equation of a line. 

3. Do Now – Match the equations on the left with an equations on the right
Point-Slope 
Slope-intercept 
y – 8 = ½ (x + 6)
y + 2 = 3(x – 4) 
y – 9 = x + 4 
y = 3x – 14
y  = x + 13 
 y = ½ x – 2 
y = ½x + 11
y = 3x – 5    

4. Point – Slope Form 
The equation of  a slope is 

5. Point – Slope 

6. Example 1: Write an Equation
Write an equation in point-slope form for the line that passes through (3, -2) with a slope of ¼. Then graph the equation. y - (-2) = ¼ (x – 3) y + 2 = ¼ (x – 3) To graph plot (3, -2) and use the slope to move.

7. Writing Equations in Point-Slope
Given the Slope and the Point 
Given Two Points 
Substitute m, and the coordinates are (x1, y1). 
Rewrite the equation in the needed form. 
Find the slope.
Choose one of the two points to use. 
Follow the steps for writing the equation with the slope and one point. 

8. Another Example 

9. Example 2: Standard Form
Write y – 1 = - 2/3(x – 5) in standard form. Hint: What is standard form?

10. Solution y – 1 = -2/3 (x – 5) 3(y –1) = 3(-2/3)(x – 5)
Multiply both sides by 3. 
3(y – 1) = -2(x – 5) 
3y – 3 = -2x + 10 
Distribute to eliminate ( )
3y – = -2x
Add 3 to both side  
3y = -2x + 13 
3y + 2x = -2x + 2x + 13
Add 2x to both side 
2x + 3y = 13

11. Example 3: Slope – Intercept Form
Write y + 3 = 3/2 (x + 1) in slope – intercept form. y + 3 = 3/2 (x + 1) y + 3 = 3/2x + 3/2 distribute 3/2 y = 3/2x + 3/2 - 3 subtract 3 from both sides y = 3/2x + 3/2 - 6/2 change 3 to 6/2, we need the same denominator y = 3/2x - 3/2

12. Activity – Match each graph to the appropriate equation. 1
y + 7 = 3(x + 2) 
y – 7 = 3(x – 2) 

13. Activity 
y + 2 = ½ (x – 2) 
y – 2 = ½ (x + 2)
y – 2 = 2 (x + 2)    

14. Classwork/ Homework 
Classwork: 4 – 3 Skills Practice (Odd) Homework: 4 – 3 Skills Practice (Even)