1. Point Slope Form Standard Form
Writing Equations of Lines
Point Slope Form Standard Form

2. Point Slope Form
Variable
Variable
y – y1 = m(x – x1)
Slope
(x1, y1)

3. Steps Write the equation: Determine the slope Substitute slope for “m”
Substitute values from a point for x1 and y1
Eliminate any “double signs” (i.e. +-, --, etc.)

4. Why does the point-slope form work?
Find the slope between (x1, y1) and (x, y).
Reflexive
property
Point-Slope Form

5. Write the equation of the line with slope 3 and passing through the point (1, 5).
Use Point-Slope Form
y – y1 = m(x – x1)

6. Write the equation of the line with slope ¾ and passing through the point (-5, 3).
Use Point-Slope Form
y – y1 = m(x – x1)

7. Write the equation of the line with slope -2/3 and passing through the point (2, -4).
y – y1 = m(x – x1)

8. Find the slope let's use (3, -1)
Write the equation of the line passing through the points (-2, 6) and (3, -1).
Find the slope
y – y1 = m(x – x1)
let's use (3, -1)

9. Find the slope let's use (4, 3)
Write the equation of the line passing through the points (4, 3) and (6, 8).
Find the slope
y – y1 = m(x – x1)
let's use (4, 3)

10. Find the slope let's use (4, -3)
Write the equation of the line passing through the points (4, -3) and (-7, -1).
Find the slope
y – y1 = m(x – x1)
let's use (4, -3)

11. Standard Form Constant Both Can’t Be 0 Integer When Possible
Any Constant

12. Steps Basically, solve for C Get the “x” and “y” on one side of the =
Get the constant on the other side of the =

13. Convert y = 3x + 2 to standard form.
multiply both sides by -1

14. Convert y = 6776x to standard form.
multiply both sides by -4

15. Convert y = 6776x to standard form.
multiply both sides by 7

16. Convert y = 6776x to standard form.
multiply both sides by -2

17. Convert y = 6776x to standard form.
multiply both sides by 15

18. More on Slope Parallel lines have the same slope
Perpendicular lines have opposite reciprocal slopes
Parallel Lines
Perpendicular Lines

19. What is the slope of the given line?
Write the equation of the line parallel the line 4x – 5y = 7 that passes through the point (-3, 7)
What is the slope of the given line?
y – y1 = m(x – x1)

20. What is the slope of the given line?
Write the equation of the line perpendicular the line 3x + 2y = 9 that passes through the point (2, 5)
What is the slope of the given line?
y – y1 = m(x – x1)