1. Section 2-4: Writing Linear Equations
We have already seen standard form of an equation, but this form isn’t very useful.
We are going to use slope-int. and point-slope form to write equations.

2. Slope-Intercept Form
y = ______ [ ____ = mx + b]
Remember, MOST of the time we will still have ______ in the final equation.
m is the _______
b is the __________

3. Write the equation of the line.
First (and easiest) b = ?
b =
m = ?
m =
y = x y

4. Write the equation of the line.
b = ?
b =
m = ?
m =
y = x y

5. Write the equation of the line.
b = ?
b =
m = ?
m =
y = x y

6. Give the slope and y-int. of each equation.
y = -4x + 3
m =
b =
y = 5 - 1/2x
8x + y = 3/4
m =
b =
4x - 2y = 10

7. Give the slope and y-intercept of each line.
y = -1/3x
m =
b =
y = 5
m =
b =

8. Given the slope and y-int., write the equation of the line.
m = 0, b = 10
m = 1, b = 0
m = 0, b = 0
m = -3, b = 1
m = -2/5, b = -4

9. Given the graph, write the equation of the line.
To write the equation of a line, we need two pieces of information: ___________ ________________
You should be able to get these from _________.

10. Point-Slope Form
Use this form if you are given _________, or a __________. (as long as the pt. isn’t b)
____________________
(x1, y1) is one of the given points.
Use the points to calculate m.

11. Give the equation of the line.
the line goes through (3, 2) & (5, 4).
m =
choose either point, we’ll use (3, 2). Plug in 3 for ___ & 2 for ____.
____________

12. Write the equation.
y - 2 = 1(x - 3)
Simplify.
______________
add two to both sides
__________

13. Give the equation of the line through the points (4, 3) and (7, -2)
m =
plug either point.
y - 3 =
y =

14. Give the equation of the line with x-int. 3 and y-int 2.
Because we know the y-int. (b), we only need the slope.
m =
y =