Lesson 13-3 Pages 678-681

Subtracting Polynomials

What you will learn!1. How to subtract polynomials.

What you really need to know!

To subtract polynomials, subtract like terms.

Example 1: Find the difference:

7a7a ++ 44−− (9a(9a ++ 2)2)

-2a-2a ++ 22

(7a + 4) − (9a + 2)

Example 1b: Find the difference:

(8b2 + 6) − (3b2 + 6b + 1)

8b8b22 ++ 66

−−(3b(3b

22 ++ 6b6b ++ 1)1)

5b5b22 −− 6b6b ++ 55

Example 2: Find the difference:

(4 x - 8) − (3x + 9)

4x4x −− 88

−−(3(3xx

++ 9)9)

xx −− 1717

Example 2b: Find the difference:

(7ab + 2b2) − (3a2 + ab + b2)

7ab7ab ++ 2b2b22

−−(3a(3a22 ++ abab ++

bb22))

--3a3a22 ++ 6ab6ab ++ bb22

Example 3:

The length of a rectangle is x2 – 9 x + 10 units. The width is x2 –x units. How much longer is the length than the width?

Example 3: Find the difference:

(x2 – 9x + 10) − (x2 - x)

xx22 −− 9x9x ++ 1010

−− (x(x22 −− x)x)

−− 8x8x ++ 1010

Page 680

Guided Practice

#’s 3-9

Pages 678-679 with someone at home and

study examples!

Read:

Homework: Pages 680-681

#’s 10-26 even

#’s 30-45 all

Practice Quiz 1

Page

756

Lesson 13-3