1. Writing the Equation of a Line

2. Review of Slope-Intercept Form
The slope-intercept form of a linear equation is
y = mx + b.
m represents the slope
b represents the y-intercept

3. Write the Equation in Slope-Intercept Form
5. The slope is 2; the y-intercept is 5
6. The slope is -4; the y-intercept is 0
7. The slope is - ; the y-intercept is -3
8. The slope is ; the y-intercept is
y = 2x + 5
y = -4x
y = - x – 3

4. Find the Equation of the Line Given the Slope and y-intercept
Substitute m and b into y = mx + b
m = -3, b = 1
m = -2, b = -4
m = 0, b = 10
m = 1, b = 0
m = 0, b = 0
y = -3x + 1
y = -2x - 4
y = 0x + 10, y = 10
y = 1x + 0, y = x
y = 0x + 0, y = 0

5. Slope-intercept form of an equation
Given the slope and y-intercept, write the equation of a line in slope-intercept form.
1) m = 3, b = -14
2) m = -½, b = 4
3) m = -3, b = -7
4) m = 1/2 , b = 0
5) m = 2, b = 4
Slope-intercept form of an equation
Y = mx + b

6. Example 1
b = -3
m =
y = x - 3 x y +2 +3

7. Example 2
b = 1
m =
y = x + 1 x y +1 -2

8. Example 3
b = 4
m = 0/1= 0
y = 0x + 4, y = 4 x y

9. Write an Equation in Slope-Intercept Form
10. Write the Equation for this line
Slope = m =
y-intercept = b 2
= -2 3

10. Write an Equation in Slope-Intercept Form
11. Write the Equation for this line
Slope = m =
y-intercept = b 4 5
= 3

11. Write an Equation in Slope-Intercept Form
12. Write the Equation for this line
Slope = m =
y-intercept = b
= -2 2
= 1 4