1. Lesson 4.2 Multiplying Polynomials Objectives:
• Use the BOX method to multiply polynomials
Multiplying Polynomials

2. 2x2 for a Binomial x Binomial
Concept: Using the Box method
Multiply: (x + 2)(x + 4)
Step 1: Draw the box. (What are the dimensions?)
2x2 for a Binomial x Binomial

3. Concept: Using the Box method
Multiply: (x + 2)(x + 4)
Step 2: Set up the box
I’m going to need a lot more room than this…

5. Concept: Using the Box method
Multiply: (x + 2)(x + 4)
Step 3: Multiply row by column.
……………………………………………….
This part is kind of like
filling in a multiplication
times table.

6. Click to advance

7. Concept: Using the Box method
Multiply: (x + 2)(x + 4)
Step 4: Combine like terms.
………………………………..
You might notice that
the “like” terms kind
of line up with each
other diagonally.

8. You
Rock

9. That’s amazing.
LET’S DO
THAT AGAIN!
FASTER!!!

10. 2x2 for a Binomial x Binomial
Concept: Do it Again
Hold on! Here we go!!!
2x2 for a Binomial x Binomial

14. YOU TRY
What Do I Do First?????

15. 2x2 for a Binomial x Binomial

19. Concept: Other Sized Polynomials
Does the Box Method work with any size?
YES!
This is a binomial times a trinomial. What will the dimensions of the box be?
2 X 3

20. Concept: Other Sizes cont…
2x2
+10x –6
10x3
50x2
–30x
30x
6x2
–18 5x +3
10x3 + 50x x + 6x2 – 30x – 18
10x3 + 56x2 – 18

21. Concept: You Try!!! Multiply. (x + 2)(x – 8) x2 – 6x – 16
3. (2x – 5y)(3x + y)
x2 – 6x – 16
2x3 – x2 – 29x + 28
6x2 – 13xy – 5y2