Lesson 7.4: Constant Rate of Change

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Lesson 7.4 Constant Rate of Change

• Pre Algebra

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Definitions

• Linear Relationships Relationships that have a
  straight-line graph.
• Linear equations are an example of a linear
  relationship.
• Constant Rate of Change The rate of change
  between ANY two data points is the same or
  constant. (Linear relationships have a constant
  rate of change).

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Examples
Find the constant rate of change for each linear
function.
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Check Your Progress
Find the constant rate of change for each linear
function.
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Definitions

• Direct Variation A special type of a linear
  equation that always passes through the origin
  and also represents a proportional linear
  relationships.
• Written in the form

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Examples
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Check Your Progress
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• In the equation , is called
  the Constant of Variation (also referred to as
  the constant of proportionality). The direct
  variation can also be written as

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Example
The cost of cheese varies directly with the
number of pounds bought. Suppose 2 pounds cost
8.40.
Write an equation that could be used to find the
unit cost of cheese.
Find the cost of 3.5 pounds of cheese.
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Check Your Progress
The cost of peaches varies directly with the
number of pounds bought. Suppose 3 pounds cost
4.50.
Write an equation that could be used to find the
unit cost of peaches.
Find the cost of 5.5 pounds of cheese.
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Classwork

• Pg. 380
• 7-15 (odd)

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Homework

• Worksheet 7.4 Practice
• All