1. Writing an Equation of a Line
Objective: SWBAT identify slope as a linear
pattern and use it to write
equations in y = mx+b form.

2. Vocabulary:
Equation
of a Line an equation that makes a straight line
when it is graphed
y = mx + b
m = slope and b = y-intercept

3. How do you find the y-intercept (b)?
Look at the graph and look where the line intersects on the y-axis.
y-intercept: (0, -3)
How do you find the slope (m)?
Look at the line on the graph
and look where the line intersects
nicely throughout the graph.
slope: 𝟐 𝟏 or 2
How do you write an equation of a line?
Plug in the above information into the y = mx + b.
Equation: y = 2x – 3

4. Practice Problems:
Identify slope as a linear pattern and use it to write equations in y = mx+b form.
Slope = ____ y-intercept = ______ Slope = ____ y-intercept = ______
Equation = ________________ Equation = ________________
𝟐 𝟏 or 2
(0, 2)
− 𝟏 𝟐
(0, -3)
y = - 𝟏 𝟐 x – 3
y = 2x + 2

5.
Slope = ____ y-intercept = ______ Slope = ____ y-intercept = ______
Equation = ________________ Equation = ________________
𝟐 𝟑
(0, 0)
(0, 1)
- 1
y = 𝟐 𝟑 x + 1
y = - x
y = -1x
y = - x + 0
y = -1x + 0