Lesson 13-4 Pages 683-686

Multiplying a Polynomial by

a Monomial

What you will learn!1. How to multiply a polynomial by a monomial.

What you really need to know!

The distributive property can be used to multiply a polynomial by a monomial.

Example 1: Find the product:

-8(3x + 2)

-8(3x) + -8(2)

-24x + -16

-24x – 16

Example 1b: Find the product:

(6x – 1)(-2x)

(6x)(-2x) – (1)(-2x)

-12x2 − -2x

-12x2 + 2x

Example 2: Find the product:

4b(-a2 + 5ab + 2b2)

4b(-a2) + 4b(5ab) + 4b(2b2)

-4a2b +20ab2 + 8b3

Example 3:

The length of a dog run is 4 feet more than three times its width. The perimeter of the dog run is 56 feet. What are the dimensions of the dog run?

w = width

4 + 3w = length

Perimeter = 2(L) + 2(w)

56 = 2(w) + 2(4 + 3w)

56 = 2w + 8 + 6w

56 = 2w + 8 + 6w

56 = 8w + 8

48 = 8w

6 = w

Width = 6, Length = 22

Page 685

Guided Practice

#’s 4-10

Pages 683-684 with someone at home and

study examples!

Read:

Homework: Pages 685-686

#’s 12-30 even

#’s 33-46 all

Prepare for Mid-Test!

Pages 698-699

#’s 9-40Odd Answers in Back of Book!

Page

756

Lesson 13-4