1. Sam opened a savings account that compounds interest at a rate of 3% annually. Let P be the initial amount Sam deposited and let t be the number of years the account has been open. a. If Sam opened the account with $500 and made no deposits or withdrawals, how much is in the account 10 years later? b. What is the least number of years it would take for such an account to double in value?
Problem of the Day

2. Section 7-2 Solving Exponential Equations and Inequalities

3. Then Now Objectives You graphed exponential function.
Solve exponential equations.
Solve exponential inequalities.

4. Common Core State Standards
Content Standards
A.CED.1 – Create equations and inequalities in one variable and use them to solve problems.
Mathematical Practices
2) Reason abstractly and quantitatively.
Common Core State Standards

6. Solve the equation: 4 2𝑛−1 =64
Example 1

7. Solve the equation: 5 5𝑥 = 125 𝑥+2
Example 1

8. Solve each equation: 3 𝑥 = 9 4 2 5𝑥 = 4 2𝑥−1
Example 1

9. In 2000, the population of Phoenix was 1,321,045
In 2000, the population of Phoenix was 1,321, By 2007, it was estimated at 1,512,986.
Write an exponential function that could be used to model the population of Phoenix. Write x in terms of the number of years since 2000.
Predict the population of Phoenix in 2020.
Example 2

11. A manufacturer distributed 3.2 million aluminum cans in 2005.
In 2010, the manufacturer distributed 420,000 cans made from the recycled cans it had previously distributed. Assuming that the recycling rate continues, write an equation to model the distribution each year of cans that are made from recycled aluminum.
How many cans made from recycled aluminum can be expected in the year 2050?
Example 2

13. Compound Interest: interest paid on the principal of an investment and any previously earned interest.
Vocabulary

14. Find the account balance after 20 years in $100 is placed in an account that pays 1.2% interest compounded twice a month.
Example 3

15. An investment account pays 5. 4% annual interest compounded quarterly
An investment account pays 5.4% annual interest compounded quarterly. If $4000 is placed in this account, find the balance after 8 years.
Example 3

16. An investment account pays 4. 8% annual interest compounded monthly
An investment account pays 4.8% annual interest compounded monthly. If $2200 is placed in this account, find the balance after 11 years.
Example 3

17. p.464 #9 – 15, 20, 22, 55
Homework