The document provides instructions and examples for lesson 69 on direct variation and proportional relationships. It includes instructions to complete an assignment with 5 warmup problems. It then defines key terms like constant of proportionality and dependent and independent variables. It provides examples of direct variation relationships and how to identify them based on whether the graph intersects the origin and is linear. It gives examples finding the constant of proportionality for proportional relationships.

1. Assignment:
1-->Set 69 (odds) - Due by the end of class TODAY!
... So you don't have an
assignment over Break!!
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2. Lesson 69 Warm-Up:
1) Solve and graph: 3x - 2 > 4
2) Solve: [show all steps for credit] 3/5x + 7/10 = 19/10
3) The price of the painting increased by 90% after the artist became
famous. If the new price is $2470, what was the original price?
4) Use a unit multiplier to convert 100 meters in 50 seconds to meters
per minute.
5) Write 8/9 as a percent.
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3. Lesson 69:
*constant of proportionality – the number that relates 2
variables in a direct variation
*direct variation – a proportional relationship between 2
variables in which one variable is a constant multiple of the
other, that is, the quotient of the 2 variables is a constant
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4. *dependent variable - the variable in an equation whose value is
determined by the value chosen for one or more of the other
variables
*independent variable - a variable in an equation whose value
can be freely chosen
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5. How to tell if a function is an example of direct variation:
--the graph intersects the origin
--the function is linear (forms a line)
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6. Lesson 69 Examples:
pg. 467
A) p = 3s
c. of p. = 3
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7. B) No - not proportional
Not direct variation - Sergio's age isn't a constant multiple of
Fernando's.
C) 20 gallons 30 gallons C. of P. =
166 pounds X 166 pounds
20 gallons
p = 8.3g
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