Polynomials By C. D.Toliver. Polynomials An algebraic expression with one or more terms –Monomials...

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Transcript of Polynomials By C. D.Toliver. Polynomials An algebraic expression with one or more terms –Monomials...

PolynomialsPolynomialsBy C. D.ToliverBy C. D.Toliver

PolynomialsPolynomials• An algebraic expression with one or

more terms– Monomials have one term, 3x– Binomials have two terms, 3x

+ 4– Trinomials have three terms, x2

+ 3x + 4

Review:Review: Collecting Like Terms Collecting Like Terms

• You simplify polynomial expressions by collecting like terms

• Like terms have the same variable and the same exponent.2a, 5a, -7a are like terms

2a, 5b, 6c are not like terms a3, a2, a are not like terms• Constants are also like terms 2, 0.5, ¼ are like terms

ReviewReviewCollecting Like TermsCollecting Like Terms

Example 1. Simplify3x2 + 5x – 2x2 + 3x + 73x2 + 5x – 2x2 + 3x + 71x2 + 8x + 7

Review:Review: Collecting Like Terms Collecting Like Terms

Example 2. Simplify(5a + 7b + 6) + (- 8a - 9b + 5)5a + 7b + 6 + - 8a + - 9b + + 55a + 7b + 6 - 8a - 9b + 5-3a – 2b + 11

Review:Review: Collecting Like Terms Collecting Like Terms

Example 4. Simplify(5a + 7b + 6) – (8a - 6b + 5)5a + 7b + 6 - 8a - -6b -+55a + 7b + 6 - 8a + 6b - 5-3a + 13b + 1

Review:Review: Distributive Property Distributive Property

• We also learned that parenthesis mean to multiply.

• We use the distributive property to multiply polynomials

• The distributive property says: a(b+c) = a(b) + a(c)

Review:Review: Distributive Property Distributive Property

Example 1 Multiply3(x+y) 3(x) + 3(y)3x +3y

Review:Review: Distributive Property Distributive Property

Example 2. Multiply4(2x – 3)4(2x) + 4(-3)8x -12

Review:Review: Distribute and Collect Distribute and Collect

• For more complex expressions you may need to distribute and collect like terms.

• Distribute first• Then collect

Review:Review: Distribute and Collect Distribute and Collect

Example 1. Distribute and Collect6(x + 5) - 2(2x – 8)6(x) +6(5) -2(2x) -2(-8) Distribute6x + 30 – 4x + 16 Collect2x + 46

Review:Review: Distribute and Collect Distribute and Collect

Example 2. Distribute and Collect3(2x - 4) + 7(x – 2) 3(2x) + 3(-4) +7(x) + 7(-2)Distribute6x - 12 + 7x - 14 Collect13x - 26

Review:Review: Distribute and Collect Distribute and Collect

Example 3. Distribute and Collect5(y - 3) + 4(6 - 2y)5(y) +5(-3) +4(6) +4(-2y)Distribute5y - 15 +24 – 8y Collect-3y + 9

Multiply PolynomialsMultiply Polynomials• In the previous examples, we were

multiplying polynomials by a monomial, e.g., 3 (x+2)

• 3 is a monomial• x+2 is a polynomial• What happens when you multiply two

polynomials, e.g., (x + 4)(x+2)?

Multiply PolynomialsMultiply Polynomials• We will look at three different

methods to multiply polynomials• You may prefer one method over

another• Today we will practice all three

methods

Multiply PolynomialsMultiply PolynomialsDistributive MethodDistributive Method

Example 1. Multiply(x + 4)(x + 2)x(x+2) + 4(x+2) Distributex(x) + x(2) + 4(x) +4(2) Distributex2 + 2x + 4x + 8 Collectx2 + 6x + 8

Multiply PolynomialsMultiply PolynomialsVertical MethodVertical Method

Example 1. Multiply(x + 4)(x + 2) Rewrite vertically

X + 4X + 22x + 8 Multiply

x2 + 4x Multiply x2 + 6x + 8 Combine

Multiply PolynomialsMultiply PolynomialsBox MethodBox Method

Example 1. Multiply(x + 4)(x + 2)=x2 + 6x + 8

x2 2x

4x 8

x +2

x

+4

Multiply PolynomialsMultiply PolynomialsDistributive MethodDistributive Method

Example 2. Multiply(x - 3)(x + 5)x(x+5) - 3(x+5) Distributex(x) + x(5) - 3(x) -3(5) Distributex2 + 5x - 3x - 15 Collectx2 + 2x - 15

Multiply PolynomialsMultiply PolynomialsVertical MethodVertical Method

Example 2. Multiply(x - 3)(x + 5) Rewrite vertically

X - 3X + 5

5x - 15 Multiply x2 - 3x Multiply x2 + 2x - 15 Combine

Multiply PolynomialsMultiply PolynomialsBox MethodBox Method

Example 2. Multiply(x - 3)(x + 5)=x2 + 2x - 15

x2 -3x

5x -15

x -3

x

+5

Multiply PolynomialsMultiply PolynomialsDistributive MethodDistributive Method

Example 3. Multiply(2x + 1)(x - 4)2x(x-4) + 1(x-4) Distribute2x(x)+2x(-4)+1(x)+1(-4) Distribute2x2 - 8x + 1x -4 Collect2x2 - 7x - 4

Multiply PolynomialsMultiply PolynomialsVertical MethodVertical Method

Example 3. Multiply(2x + 1)(x - 4) Rewrite vertically

2x + 1x - 4

-8x - 4 Multiply 2x2 + 1x Multiply 2x2 - 7x - 4 Combine

Multiply PolynomialsMultiply PolynomialsBox MethodBox Method

Example 3. Multiply(2x + 1)(x - 4)=2x2 - 7x - 4

2x2 1x

-8x -4

2x +1

x

-4

Multiply PolynomialsMultiply PolynomialsDistributive MethodDistributive Method

Example 4. Multiply(2x + 3)(3x - 4)2x(3x-4)+3(3x-4) Distribute2x(3x)+2x(-4)+3(3x)+3(-4)Distribute6x2 - 8x + 9x - 12 Collect6x2 + 1x - 12

Multiply PolynomialsMultiply PolynomialsVertical MethodVertical Method

Example 4. Multiply(2x + 3)(3x - 4) Rewrite vertically

2X + 3 3X - 4 -8x - 12 Multiply

6x2 + 9x Multiply 6x2 + 1x - 12 Combine

Multiply PolynomialsMultiply PolynomialsBox MethodBox Method

Example 4. Multiply(2x + 3)(3x - 4)=6x2 + 1x - 12

6x2 9x

-8x -12

2x +3

3x

-4