1. Chapter 8: Polynomials and Factoring
8.3: Multiplying Binomials

2. 8.3: Multiplying Binomials
Goals: To multiply two binomials and to multiply a binomial by a trinomial

3. 8.3: Multiplying Binomials
To find the product of two binomial:
Use repeated distribution
Example:
1. (2x + 1)(x + 2)

4. 8.3: Multiplying Binomials
You try:
2. (3x – 4)(x + 5)

5. 8.3: Multiplying Binomials
Example
3. What is the simplified form of (x + 4)(2x – 1)?

6. 8.3: Multiplying Binomials
Changing a quadratic in intercept form to standard forms requires using the FOIL method
First
Outer
Inner
Last
Multiply the terms: first, outer, inner, last
Combine any like terms

7. 8.3: Multiplying Binomials
Example:
4. (x + 3)(4x + 9)

8. 8.3: Multiplying Binomials
You try:
5. What is the simplified form of (3x + 1)(4x – 2)?

9. 8.3: Multiplying Binomials
You try:
6. What is the simplified form of (x – 7)(2x – 3)?

10. 8.3: Multiplying Binomials
Application:
7. What is the area of a rectangle with length 2x + 1 and width 5x – 2?

11. 8.3: Multiplying Binomials
You try:
8. The radius of a cylindrical gift box is (2x + 3) in. The height of the gift box is twice the radius. What is the surface area of the cylinder? Write your answer as a polynomial in standard form. (SA = 2πx2 + 2πrh)

12. 8.3: Multiplying Binomials
Product of a Trinomial and a polynomial:
Repeated distribution
Example:
9. What is the simplified form of (2x2 – 5x + 4)(x + 3)?

13. 8.3: Multiplying Binomials
You try:
10. What is the simplified form of (k2 – 4k + 3)(k – 2)?

14. 8.3: Multiplying Binomials
Homework Page 501 #8-34 (even) (skip 30)