1. 1-2 MODELING RELATIONSHIPS WITH VARIABLES MS. BATTAGLIA – ALGEBRA 1 CP OBJECTIVE: DESCRIBE RELATIONSHIPS BETWEEN SETS OF DATA, AND USE VARIABLES AS A SHORTHAND WAY TO EXPRESS RELATIONSHIPS.

2. WARM UP Find the mean, median, and mode of the following set of numbers: 10, 1, 3, 6, 4, 3, 7

3. EXAMPLE One Direction is designing a stage to use in its new music video. Their set designer made the sketches shown below. # of sides 3 4 5 6 # of triangular regions 1 1)Complete the table. 2)What is the relationship between the number of sides a stage has and the number of triangle regions created by the line segments? 3)One Direction plans to use a 12-sided stage. How many triangular regions can the designer form with the segments starting at one corner?

4. DEFINITIONS Variable– A letter that represents a number. The value of a variable can change. (2x + 6) Variable Expression – Mathematical phrase that uses numbers, variables, and operation symbols. Term – A number, variable, or the product or quotient of a number and a variable

5. EXAMPLE 1)Could you use a letter other than a or b? 2)How many terms does the expression have? 3)How many terms does the expression s – 2 have?

6. EXAMPLE Each chicken burrito at Chipotle costs $6.25. a) Write an equation you can use to find the total cost when you know the number of burritos bought. b) What do the variables represent? c) A worker says 2 burritos cost $62.52. What is the mistake he made?

7. EXAMPLE Write an equation for the data in the table. c = cost of items purchased a = amount of change. Change from a $20 bill *Suppose you wrote “The cost of the items plus the amount of change equals $20. Write an equation. Cost of Items Purchased Amount of Change $20.00$0 $19.00$1.00 $17.50$2.50 $11.59$8.41

8. CLASSWORK P. 13-14 # 1, 3, 7, 9, 11, 13, 32, 33

9. HOMEWORK P. 13-14 #2, 4, 6, 8, 10, 14, 16, 20, 21, 22, 30, 31