1. Goal: Use a linear equation to model a real-life problem. Eligible Content: A1.1.2.1.1 / A1.1.2.1.3 / A1.2.1.1.1 / A1.2.1.2.1 / A1.2.1.2.2 / A1.2.2.1.3 / A1.2.2.1.4 4-2 Writing Equations given Word Problems

2. Word Problems Slope still means rate of change (y per x). y-intercept still means beginning amount. Ordered pairs are created by pairing up numbers that go together.

3. Word Problem #1 A camp program charges a registration fee and a daily amount. The total bill for 12 days is $338. The total bill for 19 days is $506. Slope is $ per day Write a linear equation that models this situation. y = 24x + 50 Use your equation to find the charge for 30 days. $770

4. Word Problem #2

5. Word Problem #3 In 2004, there were 9.97 million domestic flights in the US. In 2008, there were 9.37 million domestic flights. Let x = 0 correspond to 2000. Slope is flights per year Write a linear equation that models this situation. y = –0.15x + 10.57 Use your equation to find the number of domestic flights in 2013. 8.62 million flights

6. A.y = 3.5x + 57.65 B.y = 3.5x + 68.15 C.y = 57.65x + 68.15 D.y = –3.5x – 10 The cost of a textbook that Mrs. Lambert uses in her class was $57.65 in 2005. She ordered more books in 2008 and the price increased to $68.15. Write a linear equation to estimate the cost of a textbook in any year since 2005. Let x represent years since 2005.

7. Practice Worksheet – “4-2 Word Problems”

8. Homework Pages 229-230 #24, 31-33, 40-42 Do not graph!