1) The document contains notes from Lesson 69 which discuss direct variation and proportional relationships. It includes examples of direct variations with constants of proportionality and examples that are not direct variations. 2) The notes also define key terms like dependent variable, independent variable, and constant of proportionality. It provides instructions on how to determine if a function represents direct variation by looking at the graph intersecting the origin and being linear. 3) Examples are worked through, including one where the constant of proportionality is calculated from given values in a direct variation relationship.

1. Lesson 69.notebook
February 21, 2014
Assignment:
1-->Set 69 (odds) - Due Monday [2/24]
2-->Test #10 - Friday [2/28]

2. Lesson 69.notebook
February 21, 2014
Lesson 69 Warm-Up:
1)
Solve and graph:
2)
Solve:
3x - 2 > 4
[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.

3. Lesson 69.notebook
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
February 21, 2014

4. Lesson 69.notebook
February 21, 2014
*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

5. Lesson 69.notebook
How to tell if a function is an example of direct variation:
--the graph intersects the origin
--the function is linear (forms a line)
February 21, 2014

6. Lesson 69.notebook
Lesson 69 Examples:
pg. 467
A) p = 3s
c. of p. = 3
February 21, 2014

7. Lesson 69.notebook
February 21, 2014
B) No - not proportional
Not direct variation - Sergio's age isn't a constant multiple of
Fernando's.
C)
20 gallons
166 pounds
30 gallons
X
p = 8.3g
C. of P. =
166 pounds
20 gallons