1. Warmups Find the slope. (2, -5) (3, 1) (-6, 4) (3, 7)
Find the value of r.
(5, r) (-2, 4) m = -1
(r, 5) (-2, r) m =

2. Writing Linear Equation in Point-Slope and Standard Forms
SLO: Write a linear equation in point-slope form

3. Point-Slope Form (x1 ,y1) m = rise = slope point run
y – y1 = m(x – x1)
(x1 ,y1) m = rise = slope
point run

4. Writing in Point-Slope
Given a point and a slope, write an equation in point-slope form
y – y1 = m(x – x1)
Example 1: (3,8) m = 2
y – 8 = 2 (x – 3)
x1, y1

5. Opposite sign than ordered pair!
Example 2
y – y1 = m(x – x1)
(-6,1) m = -4 (5,-2) m=
y – 1 = -4(x + 6)
x1, y1
Opposite sign than ordered pair!

6. Examples 3 & 4 y – y1 = m(x – x1) 3. (2,5) m = 0 y – 5 = 0(x – 2)
4. (-1,6) m = undefined (no)
x = -1

7. Example 5 (6,3) (-8,5) Steps: Find slope Pick an ordered pair
Given 2 ordered pairs, write an equation in point-slope form:
(6,3) (-8,5)
Steps:
Find slope
m = y2 – y1
x2 – x1
Pick an ordered pair
There are 2 possible answers!
m = 5 – 3
-8 – 6
y – 3 = -1/7(x – 6) or
y – 5 = -1/7(x + 8)
= 2
-14
= -1 7

8. Example
Given 2 ordered pairs, write an equation in point-slope form:
(-1,-7) (1,3) (-4,6) (-2,5)

9. You Try
Given 2 ordered pairs, write an equation in point-slope form:
(2,-6) (2,5) (5,3) (-2,3)