1. Review: 10.1b Mini-Quiz
Five hundred dollars ($500) is deposited in an account.
At the end of 2 years, the balance in the account is $605.
The interest earned on the account is compounded annually. What is the interest rate?
The mathematical model used to find the interest earned on an account is: A = P(1 + r)t where A is the balance in the account, P is the amount deposited, r is the annual interest rate (in decimal form), and t is the number of years.

2. Class Greeting

3. Chapter 10 Quadratic Equations and Functions
Lesson 10-2a
Solving Quadratic Equations by
Completing the Square

4. Objective: Students will learn how to solve quadratic equations by completing the square.

5. Vocabulary
a method used to make an equation a Perfect Square Trinomial equation.

6. Completing the Square
If your equation is prime, you can make it a Perfect Square Trinomial equation to find the solutions.
x2 – 10x = 0
x2 – 10x is PRIME
COMPLETE THE SQUARE
x2 – 10x = -18
Divide -10 by 2 and square the answer, you get 25 now add 25 to both sides
x2 – 10x + 25 =7
(x – 5)2 = 7 = 7
(x – 5)2

7. = Solve an Equation by Completing the Square Solve: x2 –18x + 5 = –12.64
x – 9 = ±8
x – = ±8 + 9
x = 9 ± 8
x = or x = 9 – 8
x = x = 1
Answer: x = 1, 17

8. Example 2 – Completing the Square: Leading Coefficient Is Not 1
Solve 2x2 + 5x = 3 by completing the square.
The solutions are:
and x x

9. Lesson 3 CYP3 Solve x2 – 8x + 10 = 30. A. {–2, 10} B. {2, –10}
D. Ø A B C D
Lesson 3 CYP3

10. Lesson Summary: Objective: Students will learn how to solve quadratic equations by completing the square.

11. Preview of the next Lesson: Objective: Students will solve word problems involving quadratic equations by completing the square.

12. Do not round your answers.
Homework
/3,11,
Do not round your answers.
Leave your answers as square roots.

13. Stand Up Please