1. COURSE 3 LESSON 3-3
Understanding Slope
Using coordinates, find the slope of the line between P (–2, 3) and Q (–1, –1).
slope =
change in y
change in x
3 – (–1)
–2 – (–1) =
Subtract the coordinates
of point Q from the coordinates
of point P. 4 –1
= or –4
Simplify.
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2. COURSE 3 LESSON 3-3
Understanding Slope
Find the slope of the line in the graph. Describe how one variable changes in relation to the other.
slope =
change in y
change in x
75 – 25
300 – 100 =
Use coordinates of
two points. = 50
100
Subtract.
Simplify. 1 4 =
The cost increases by $25 for every 100 miles traveled.
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3. COURSE 3 LESSON 3-3
Understanding Slope
Find the slope of each line. State whether the slope is zero or undefined.
a. line k
b. line p
slope = =
1 – (–3)
2 – 2 4
slope = = = 0
2 – 2
–2 – 3 –5
Division by zero is
undefined. The slope
of a vertical line is
undefined.
The slope of a
horizontal line
is zero.
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4. COURSE 3 LESSON 3-3
Understanding Slope
The data in the table below are linear. Use the data to find the slope. Then graph the data and the line.
x –
y –
slope = = or 2
change in y
change in x 2 1
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5. Understanding Slope x 2 4 5 9 1. Find the slope of each line.
COURSE 3 LESSON 3-3
Understanding Slope
1. Find the slope of each line.
a. line s b. line t
2. The data in the table below is linear.
Find the slope. x
y –6 –12 –15 –27 2 3
undefined –3
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