1. CHAPTER 2: Linear Equations, Inequalities and Applications LESSON 2.2 FORMULAS OBJECTIVES:

6. Warm Up What is 70% of 258? 216 is what percent of 360? 16% of what number is 80? 180.6 60% 500

7. A school has a total enrollment of 800 students. Twenty percent of the students play a sport. How many do not play a sport? If 20% play a sport then 80% do NOT play a sport. 80% of 800 = (.80)(800) = 640 In other words, what is 80% of 800? 640

8. There are 200 freshmen in a high school. 30% of them take Spanish. How many freshmen are enrolled in Spanish? 200(0.3) = 60 In other words, what is 30% of 200? 60

9. An algebra class contains 30 students. Forty percent of the students in the class are girls. How many boys are in the class? Hint: If 40% of the class are girls then 60% of the class are boys. You need to find 60% of the 30 students. (30)(.60) = 18 OR What is 60% of 30? x = 18

10. An appliance store advertises a discount of 45% off the list price of every item. Find the total cost, including a 6% sales tax, of a dishwasher that is listed at $410. First find the price with a discount: (410)(.45) = $184.50 $410 - $184.50 = $225.50 (New Price) Next, find the final price with sales tax added: $225.50(.06) = $13.53 Final Price = $225.50 + $13.53 = $239.03

11. A football is advertised on sale at a discount of 20% off its regular price of $50. How much will Jane pay for the football if there is a 5% sales tax? Discounted Price: ($50)(.20) = $10 DP = $50 - $10 = $40 Final Price: ($40)(.05) = $2 FP = $40 + $2 = $42

12. The original marked price of a video game is $43.98. During a special discount sale, the game price is reduced by 35% of the marked price. Then 15% of this reduced price is taken off at the cash register. What is the final price? First Discount Price: ($43.98)(.35) = $15.39 1 st DP = $43.98 - $15.39 = $28.59 2 nd Discount Price: ($28.59)(.15) = $4.29 Final DP = $28.59 - $4.29 = $24.30

13. Percent of Increase or Decrease Percent of Increase = Percent of Decrease =

14. Last week Dora earned $40 working part time. This week she earned $30. What is the percent of decrease?

15. The high school football team won 19 games this season. Last year the team won 15 games. The increase in wins is what percent of the wins last year?

16. In the diagram at the right DF = 20 and DE = 16. EF is what percent of DF? D EF 20 164 In other words, 4 is what percent of 20? 20%