1. Three Forms of an Equation of a Line
3.3 – The Equation of a Line
Three Forms of an Equation of a Line
Slope-Intercept Form:
This form is useful for graphing, as the slope and the y-intercept are readily visible.
Point-Slope Form:
The point-slope form allows you to use ANY point, together with the slope, to form the equation of the line.
Standard Form:
Note: A, B, and C cannot be fractions or decimals.

2. 3.3 – The Equation of a Line
Slope-Intercept Form– requires the y-intercept and the slope of the line.
m = slope of line
b = y-intercept

3. 3.3 – The Equation of a Line
Slope-Intercept Form– requires the y-intercept and the slope of the line.
m = slope of line
b = y-intercept

4. 3.3 – The Equation of a Line
Slope-Intercept Form– requires the y-intercept and the slope of the line.
m = slope of line
b = y-intercept

5. 3.3 – The Equation of a Line
Slope-Intercept Form– requires the y-intercept and the slope of the line.
m = slope of line
b = y-intercept

6. 3.3 – The Equation of a Line
Write an equation of a line given the slope and the y-intercept.

7. 3.3 – The Equation of a Line
Point-Slope Form – requires the coordinates of a point on the line and the slope of the line.

8. 3.3 – The Equation of a Line
Point-Slope Form – requires the coordinates of a point on the line and the slope of the line.

9. 3.3 – The Equation of a Line
Point-Slope Form – requires the coordinates of a point on the line and the slope of the line.

10. Writing an Equation Given Two Points
3.3 – The Equation of a Line
Writing an Equation Given Two Points
1. Calculate the slope of the line.
2. Select the form of the equation.
a. Standard form
b. Slope-intercept form
c. Point-slope form
3. Substitute and/or solve for the selected form.

11. 3.3 – The Equation of a Line
Writing an Equation Given Two Points
Given the two ordered pairs, write the equation of the line using all three forms.
Calculate the slope. or

12. 3.3 – The Equation of a Line
Writing an Equation Given Two Points
Point-slope form

13. Writing an Equation Given Two Points
3.3 – The Equation of a Line
Writing an Equation Given Two Points
Slope-intercept form

14. Write the equation of the line
(4, 0), (1, 5) m = Point-slope form Slope-intercept form

15. Write the equation of the line
(0, 3), (-4, -1) m = Point-slope form Slope-intercept form

16. Homework
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