1. 7-5
Polynomials
Warm Up
Lesson Presentation
Lesson Quiz
Holt Algebra 1

2. A polynomial is a monomial or a sum or difference of monomials.
The degree of a polynomial is the degree of the term with the greatest degree.

3. Example 2: Finding the Degree of a Polynomial
Find the degree of each polynomial.
A. 11x7 + 3x3
11x7: degree 7 3x3: degree 3
Find the degree of each term.
The degree of the polynomial is the greatest degree, 7. B.
:degree 3
:degree 4
–5: degree 0
Find the degree of each term.
The degree of the polynomial is the greatest degree, 4.

4. Check It Out! Example 2
Find the degree of each polynomial.
a. 5x – 6
5x: degree 1
–6: degree 0
Find the degree of each term.
The degree of the polynomial is the greatest degree, 1.
b. x3y2 + x2y3 – x4 + 2
Find the degree of each term.
x3y2: degree 5
x2y3: degree 5
–x4: degree 4
2: degree 0
The degree of the polynomial is the greatest degree, 5.

5. The terms of a polynomial may be written in any order
The terms of a polynomial may be written in any order. However, polynomials that contain only one variable are usually written in standard form.
The standard form of a polynomial that contains one variable is written with the terms in order from greatest degree to least degree. When written in standard form, the coefficient of the first term is called the leading coefficient.

6. Example 3A: Writing Polynomials in Standard Form
Write the polynomial in standard form. Then give the leading coefficient.
6x – 7x5 + 4x2 + 9
Find the degree of each term. Then arrange them in descending order:
6x – 7x5 + 4x2 + 9
–7x5 + 4x2 + 6x + 9
Degree 1 5 2
–7x5 + 4x2 + 6x + 9.
The standard form is
The leading
coefficient is –7.

7. Example 3B: Writing Polynomials in Standard Form
Write the polynomial in standard form. Then give the leading coefficient.
y2 + y6 − 3y
Find the degree of each term. Then arrange them in descending order:
y2 + y6 – 3y
y6 + y2 – 3y
Degree 2 6 1
The standard form is
The leading
coefficient is 1.
y6 + y2 – 3y.

8. Check It Out! Example 3a
Write the polynomial in standard form. Then give the leading coefficient.
16 – 4x2 + x5 + 9x3
Find the degree of each term. Then arrange them in descending order:
16 – 4x2 + x5 + 9x3
x5 + 9x3 – 4x2 + 16
Degree 2 5 3
The standard form is
The leading
coefficient is 1.
x5 + 9x3 – 4x

9. Some polynomials have special names based on their degree and the number of terms they have.
Monomial
Binomial
Trinomial
Polynomial
4 or more 1 2 3 1 2
Constant
Linear
Quadratic 3 4 5
6 or more
6th,7th,degree and so on
Cubic
Quartic
Quintic

10. Example 4: Classifying Polynomials
Classify each polynomial according to its degree and number of terms.
A. 5n3 + 4n
5n3 + 4n is a cubic binomial.
Degree 3 Terms 2
B. 4y6 – 5y3 + 2y – 9
4y6 – 5y3 + 2y – 9 is a
6th-degree polynomial.
Degree 6 Terms 4
C. –2x
–2x is a linear monomial.
Degree 1 Terms 1

11. Check It Out! Example 4
Classify each polynomial according to its degree and number of terms.
a. x3 + x2 – x + 2
x3 + x2 – x + 2 is a cubic polymial.
Degree 3 Terms 4
b. 6
6 is a constant monomial.
Degree 0 Terms 1
–3y8 + 18y5 + 14y is an 8th-degree trinomial.
c. –3y8 + 18y5 + 14y
Degree 8 Terms 3

12. Like terms are constants or terms with the same variable(s) raised to the same power(s). To review combining like terms, see lesson 1-7.
Remember!

13. Check It Out! Example 1
Add or subtract.
a. 2s2 + 3s2 + s
2s2 + 3s2 + s
Identify like terms.
5s2 + s
Combine like terms.
b. 4z4 – z4 + 2
4z4 – z4 + 2
Identify like terms.
Rearrange terms so that like terms are together.
4z4 + 16z4 – 8 + 2
20z4 – 6
Combine like terms.

14. Check It Out! Example 1
Add or subtract.
c. 2x8 + 7y8 – x8 – y8
Identify like terms.
2x8 + 7y8 – x8 – y8
Rearrange terms so that like terms are together.
2x8 – x8 + 7y8 – y8
x8 + 6y8
Combine like terms.
d. 9b3c2 + 5b3c2 – 13b3c2
9b3c2 + 5b3c2 – 13b3c2
Identify like terms.
b3c2
Combine like terms.

15. Polynomials can be added in either vertical or horizontal form.
In vertical form, align the like terms and add:
In horizontal form, use the Associative and Commutative Properties to regroup and combine like terms.
5x2 + 4x + 1
+ 2x2 + 5x + 2
7x2 + 9x + 3
(5x2 + 4x + 1) + (2x2 + 5x + 2)
= (5x2 + 2x2 ) + (4x + 5x) + (1 + 2)
= 7x2 + 9x + 3

16. Example 2: Adding Polynomials
A. (4m2 + 5) + (m2 – m + 6)
(4m2 + 5) + (m2 – m + 6)
Identify like terms.
Group like terms together.
(4m2 + m2) + (–m) +(5 + 6)
5m2 – m + 11
Combine like terms.
B. (10xy + x) + (–3xy + y)
(10xy + x) + (–3xy + y)
Identify like terms.
Group like terms together.
(10xy – 3xy) + x + y
7xy + x + y
Combine like terms.

17. Example 2D: Adding Polynomials
Identify like terms.
Group like terms together.
Combine like terms.

18. To subtract polynomials, remember that subtracting is the same as adding the opposite. To find the opposite of a polynomial, you must write the opposite of each term in the polynomial:
–(2x3 – 3x + 7)= –2x3 + 3x – 7

19. Example 3B: Subtracting Polynomials
(7m4 – 2m2) – (5m4 – 5m2 + 8)
(7m4 – 2m2) + (–5m4 + 5m2 – 8)
Rewrite subtraction as addition of the opposite.
(7m4 – 2m2) + (–5m4 + 5m2 – 8)
Identify like terms.
Group like terms together.
(7m4 – 5m4) + (–2m2 + 5m2) – 8
2m4 + 3m2 – 8
Combine like terms.

20. Example 3C: Subtracting Polynomials
(–10x2 – 3x + 7) – (x2 – 9)
(–10x2 – 3x + 7) + (–x2 + 9)
Rewrite subtraction as addition of the opposite.
(–10x2 – 3x + 7) + (–x2 + 9)
Identify like terms.
–10x2 – 3x + 7
–x2 + 0x + 9
Use the vertical method.
Write 0x as a placeholder.
–11x2 – 3x + 16
Combine like terms.

21. Example 3D: Subtracting Polynomials
(9q2 – 3q) – (q2 – 5)
Rewrite subtraction as addition of the opposite.
(9q2 – 3q) + (–q2 + 5)
(9q2 – 3q) + (–q2 + 5)
Identify like terms.
Use the vertical method.
9q2 – 3q + 0
+ − q2 – 0q + 5
Write 0 and 0q as placeholders.
8q2 – 3q + 5
Combine like terms.

22. Example 4: Application
A farmer must add the areas of two plots of land to determine the amount of seed to plant. The area of plot A can be represented by 3x2 + 7x – 5 and the area of plot B can be represented by 5x2 – 4x Write a polynomial that represents the total area of both plots of land.
(3x2 + 7x – 5)
Plot A. +
(5x2 – 4x + 11)
Plot B.
8x2 + 3x + 6
Combine like terms.

23. When multiplying powers with the same base, keep the base and add the exponents.
x2  x3 = x2+3 = x5
Remember!

24. Example 1: Multiplying Monomials
A. (6y3)(3y5)
(6y3)(3y5)
Group factors with like bases together.
(6 3)(y3 y5) 
18y8
Multiply.
B. (3mn2) (9m2n)
(3mn2)(9m2n)
Group factors with like bases together.
(3 9)(m m2)(n2  n) 
27m3n3
Multiply.

25. To multiply a polynomial by a monomial, use the Distributive Property.

26. Example 2A: Multiplying a Polynomial by a Monomial
4(3x2 + 4x – 8)
4(3x2 + 4x – 8)
Distribute 4.
(4)3x2 +(4)4x – (4)8
Multiply.
12x2 + 16x – 32

27. Example 2B: Multiplying a Polynomial by a Monomial
6pq(2p – q)
(6pq)(2p – q)
Distribute 6pq.
(6pq)2p + (6pq)(–q)
Group like bases together.
(6  2)(p  p)(q) + (–1)(6)(p)(q  q)
12p2q – 6pq2
Multiply.

28. Example 2C: Multiplying a Polynomial by a Monomial1 ( )
x y 2 6 xy + 8
x y 2 2 2
x y ( ) + 2 6 1 xy y x 8
Distribute 2 1
x y
x y
x y ( ) æ ç è + 2 1 6 8 xy ö ÷ ø
Group like bases together.
x2 • x ( ) æ + ç è 1
• 6 2
y • y
x2 • x2
y • y2
• 8 ö ÷ ø
3x3y2 + 4x4y3
Multiply.

29. Another method for multiplying binomials is called the FOIL method.
1. Multiply the First terms. (x + 3)(x + 2) x x = x2  O
2. Multiply the Outer terms. (x + 3)(x + 2) x 2 = 2x  I
3. Multiply the Inner terms. (x + 3)(x + 2) x = 3x  L
4. Multiply the Last terms. (x + 3)(x + 2) = 6 
(x + 3)(x + 2) = x2 + 2x + 3x + 6 = x2 + 5x + 6 F O I L

30. Example 3A: Multiplying Binomials
(s + 4)(s – 2)
(s + 4)(s – 2)
s(s – 2) + 4(s – 2)
Distribute s and 4.
s(s) + s(–2) + 4(s) + 4(–2)
Distribute s and 4 again.
s2 – 2s + 4s – 8
Multiply.
s2 + 2s – 8
Combine like terms.

31. Example 3C: Multiplying Binomials
(8m2 – n)(m2 – 3n)
Use the FOIL method.
8m2(m2) + 8m2(–3n) – n(m2) – n(–3n)
8m4 – 24m2n – m2n + 3n2
Multiply.
8m4 – 25m2n + 3n2
Combine like terms.

32. You can also use a rectangle model to multiply polynomials with more than two terms. This is similar to finding the area of a rectangle with length (2x2 + 10x – 6) and width (5x + 3):
2x2
+10x –6
Write the product of the monomials in each row and column. 5x
10x3
50x2
–30x +3
6x2
30x
–18
Add all terms inside the rectangle.
10x3 + 6x2 + 50x2 + 30x – 30x – 18
10x3 + 56x2 – 18

33. Example 4D: Multiplying Polynomials
(3x + 1)(x3 – 4x2 – 7)
Write the product of the monomials in each row and column. x3
4x2 –7 3x
3x4
12x3
–21x +1
4x2 x3 –7
Add all terms inside the rectangle.
3x4 + 12x3 + x3 + 4x2 – 21x – 7
3x4 + 13x3 + 4x2 – 21x – 7
Combine like terms.

34. Another method that can be used to multiply polynomials with more than two terms is the vertical method. This is similar to methods used to multiply whole numbers.
Multiply each term in the top polynomial by 3.
2x2 + 10x – 6
5x + 3 
Multiply each term in the top polynomial by 5x, and align like terms.
6x2 + 30x – 18
+ 10x3 + 50x2 – 30x
Combine like terms by adding vertically.
10x3 + 56x x – 18
10x3 + 56x – 18
Simplify.

35. Dividing Polynomials

36. To divide a polynomial by a monomial, divide each term of the polynomial by the monomial.

40. Lesson Quiz: Part I
Find the degree of each polynomial.
1. 7a3b2 – 2a4 + 4b – 15
2. 25x2 – 3x4
Write each polynomial in standard form. Then give the leading coefficient.
3. 24g g5 – g2
4. 14 – x4 + 3x2 5 4
7g5 + 24g3 – g2 + 10; 7
–x4 + 3x2 + 14; –1

41. Lesson Quiz: Part II
Classify each polynomial according to its degree and number of terms.
5. 18x2 – 12x + 5
quadratic trinomial
6. 2x4 – 1
quartic binomial
7. The polynomial 3.675v v2 is used to estimate the stopping distance in feet for a car whose speed is y miles per hour on flat dry pavement. What is the stopping distance for a car traveling at 70 miles per hour? ft

42. Lesson Quiz: Part I
Add or subtract.
1. 7m2 + 3m + 4m2
2. (r2 + s2) – (5r2 + 4s2)
3. (10pq + 3p) + (2pq – 5p + 6pq)
4. (14d2 – 8) + (6d2 – 2d +1)
11m2 + 3m
(–4r2 – 3s2)
18pq – 2p
20d2 – 2d – 7
5. (2.5ab + 14b) – (–1.5ab + 4b)
4ab + 10b

43. Lesson Quiz: Part II
6. A painter must add the areas of two walls to determine the amount of paint needed. The area of the first wall is modeled by 4x2 + 12x + 9, and the area of the second wall is modeled by
36x2 – 12x + 1. Write a polynomial that represents the total area of the two walls.
40x2 + 10