2. WARM UP Scuba Diving: A scuba diver starts at sea level. The pressure on the diver at a depth of d feet is given by the formula below, where P represents the total pressure in pounds per square foot. P = 64d + 2112 1.Rewrite the formula solved for d 2.If the pressure on a diver is 4032 pounds per square foot, what is the diver’s current depth? 5 Minutes Remain

3. WARM UP Scuba Diving: A scuba diver starts at sea level. The pressure on the diver at a depth of d feet is given by the formula below, where P represents the total pressure in pounds per square foot. P = 64d + 2112 1.Rewrite the formula solved for d 2.If the pressure on a diver is 4032 pounds per square foot, what is the diver’s current depth? 4

4. WARM UP Scuba Diving: A scuba diver starts at sea level. The pressure on the diver at a depth of d feet is given by the formula below, where P represents the total pressure in pounds per square foot. P = 64d + 2112 1.Rewrite the formula solved for d 2.If the pressure on a diver is 4032 pounds per square foot, what is the diver’s current depth? 3

5. WARM UP Scuba Diving: A scuba diver starts at sea level. The pressure on the diver at a depth of d feet is given by the formula below, where P represents the total pressure in pounds per square foot. P = 64d + 2112 1.Rewrite the formula solved for d 2.If the pressure on a diver is 4032 pounds per square foot, what is the diver’s current depth? 2

6. WARM UP Scuba Diving: A scuba diver starts at sea level. The pressure on the diver at a depth of d feet is given by the formula below, where P represents the total pressure in pounds per square foot. P = 64d + 2112 1.Rewrite the formula solved for d 2.If the pressure on a diver is 4032 pounds per square foot, what is the diver’s current depth? 1

7. WARM UP Scuba Diving: A scuba diver starts at sea level. The pressure on the diver at a depth of d feet is given by the formula below, where P represents the total pressure in pounds per square foot. P = 64d + 2112 1.Rewrite the formula solved for d 2.If the pressure on a diver is 4032 pounds per square foot, what is the diver’s current depth? 0

8. 3.8 Ratios and Rates GOAL: Use ratios and rates to solve real-life problems. KEY WORDS: Ratio Rate Unit Rate Unit Analysis

9. 3.8 Ratios and Rates The ratio of a to b is. If a and b, are measured in different units, then is called the rate of a per b. A unit rate is a rate per one given unit, such as 60 miles per gallon. a b a b

10. 3.8 Ratios and Rates EXAMPLE 1: Find a Ratio The tennis team won 10 of its 16 matches. Find the ratio of wins to losses. SOLUTIONRatio = = = ANSWER The win-loss ratio is 5/3, which is read as: “Five to Three.” Matches won Matches lost 10 matches 6 matches 5 3

11. 3.8 Ratios and Rates EXAMPLE 2: Find a Unit Rate You run a 10 kilometer race in 50 minutes. What is your average speed in kilometers per minute? SOLUTIONRate = = = ANSWER Your average speed is: “0.2 kilometers per minute” 10 kilometers 50 minutes 1 kilometer 5 minutes 0.2 km/min

12. 3.8 Ratios and Rates EXAMPLE 3 Your school football team won 8 out of 15 games, with no tie games. What was team’s ratio of wins to losses?

13. 3.8 Ratios and Rates EXAMPLE 4 Find the unit rate: A plane flies 1200 miles in 4 hours.

14. 3.8 Ratios and Rates EXAMPLE 5 Find the unit rate: You earn $45 for mowing 3 lawns. YOU ARE CERTIFIED!