The Equation of a Line in Slope y­intercept Form: y=mx + b
Why do you think this form is called the Slope y­intercept Form?
Example 1: a) Identify the slope of this line.
b) Identify the y­intercept.
c) Identify the equation of this line.
Special Lines ­ Horizontal
Identify the slope and y­intercept of this line. Use these values to create the equation of the line.
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Special Lines ­ Vertical
Identify the slope and y­intercept of this line. Use these values to create the equation of the line.
Intercepts
x ­ intercept:
y­intercept:
Example 2: Given: y = 5x ­ 15, what is the y­intercept? What is the x­intercept?
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Example 3: Given the graph, what are the intercepts?
Graphing Using Slope y­intercept
Example 4: Graph the line with a slope of ­2 and a y­intercept of 5.
Step 1: Plot the y­intercept
Step 2: Use the slope to plot at least two more points.
Step 3: Draw and label the line.
What is the equation of this line?
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Applications
Example 5: a) Identify the slope and vertical intercept for this graph.
b) What does the slope represent?
c) What does the vertical intercept represent?
d) What is the equation of this line?
Homework: Pg. 304: #1­8, 10
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