1-3.1 多項式的乘法

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Ꙩ뚵ꚡꪺ궼ꩫ

썄룑꩒

닄ꑇ뎹 Ꙩ뚵걏

NOTE:

Q. 결꒰믲 2x x 3x = 6x2_?

NOTE:

Q. 녱덯꣢썄ꕩꕈ땯뉻 2 ꚸꙨ뚵 ꚡ궼ꕈ 1 ꚸꙨ뚵ꚡ라걏둘 ꚸꙨ뚵ꚡ?

NOTE:

Ꙩ뚵ꚡꪺ궼ꩫ

(2

x

+ ×

3) (3

x

+

4)

꓀끴ꯟ (a + b)(c + d) = ac + ad + bc + bd m n m n a _×a ₌a +

꣒썄

1

군뫢ꑕꙃꙕꚡ

1.

2. ꣒썄

1

2

(3

x

+ − − +

x

1)(

x

3)

2

2 (3

x

+

2)

꓀끴ꯟ (a + b)(c + d) = ac + ad + bc + bd

궼ꩫꪺꪽꚡ륂뫢

(

3

1 )(

x

−

3)

3 x

x

+

−

(3

x

+

1)(

x

−

3)

Ꙑꚸ뚵맯믴 꿊뚵룉0

x)

#1 #2 #3 49

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Ꙩ뚵ꚡꪺ궼ꩫ

썄룑꩒

닄ꑇ뎹 Ꙩ뚵걏

NOTE:

Q.ꪽꚡ륂뫢껉ꚳ꿊뚵굮ꯧ믲뿬?

NOTE:

ꗎꪽꚡ군뫢

꣒썄

2

2 ( 2− −x 5)(3 6 )− x

1.

궰뺭뇆ꙃ

2.

Ꙑꚸ뚵맯믴ꅂ꿊뚵룉0

3.

ꗽ뱧낪ꚸꚡ ꝑꗎ궼ꩫ꒽ꚡ군뫢

꣒썄

3

2 (2x−5) 깴ꪺꖭꓨ꒽ꚡ (a – b)2_{= a}2_{– 2ab + b}2 #4 #5

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Ꙩ뚵ꚡꪺ궼ꩫ - ꣒썄룑꩒

NOTE:

Q1. 결꒰믲 –3 ꕩꕈꗽꥍ 2 궼 끟꣓? Q2. ꗑ꯼볆ꯟꪾ륄 2 ꚸꙨ뚵ꚡ 궼ꕈ 3 ꚸꙨ뚵ꚡ녯꣬ꪺ떲 ꩇ걏둘ꚸꙨ뚵ꚡ?

NOTE:

꣒썄

1. 돦뚵궼ꕈ돦뚵

뻇ꗍ뵭닟

군뫢

군뫢 2 3

( 3 ) (2 )

−

x

×

x

3 2 ( 3 ) ( ) 3 x x − ×

군뫢

군뫢(1) (2)

꣒썄

2. 돦뚵궼ꕈꙨ뚵

뻇ꗍ뵭닟 2

( 3 ) ( 5

−

x

× − +

x

8)

2 (4 3) x x − − 2 2 ( 2 ) (3− x × x − +x 2)

꣒썄

3. ꣢뚵궼ꕈ꣢뚵

뻇ꗍ뵭닟 군뫢

군뫢

(3

x

2

− × − +

1) ( 2

x

3)

2 (x− × −4) ( 6x +x) #6 #7 #8 51

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Ꙩ뚵ꚡꪺ궼ꩫ - ꣒썄룑꩒

NOTE:

Q. ꕼꭨ륂뫢ꪺ뚶Ꟈ결꛳?

NOTE:

Q. ꣏ꗎ꓀싷ꭙ볆ꩫꚳ꿊뚵굮ꯧ 믲뿬?

꣒썄

4. ꗽ궼ꙁꕛ듮

뻇ꗍ뵭닟 군뫢

군뫢

(5

x

−

1)(3

x

+ −

2) (3

x

−

4)( 2

− −

x

6)

( 2 4 )(3 5 ) ( 2− − x + x − − x+4)( 8 3 )− + x

꣒썄

5. Ꙩ뚵궼ꕈꙨ뚵 (ꪽꚡ)

뻇ꗍ뵭닟

군뫢

군뫢 2 2

(2 3

−

x

+

5 ) (4

x

×

x

+

7)

2 ( 7− − × −x 4) (x 6x −3)

꣒썄

6. ꓀싷ꭙ볆ꩫ(ꚳ꿊뚵)

뻇ꗍ뵭닟

군뫢

ꝑꗎ꓀싷ꭙ볆ꩫ군뫢 3 2

(6

x

−

2 x

+ ×

1) (2

x

+ +

x

6)

2 3 (2x −13) (× − − +x x 1) #9 #10 #11

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Ꙩ뚵ꚡꪺ궼ꩫ - ꣒썄룑꩒

NOTE:

Q. Ꙩ뚵ꚡ곛떥걏꒰믲띎ꯤ?

NOTE:

Q. 띑띑곝 (–3x – 5)2_ꥍ (3x + 5)2_{깩뙽ꯡꑀ꒣ꑀ볋?}

NOTE:

Q. ꯧ믲ꪾ륄굮녎 5x – 2x2_꧱ Ꙣꑀ닕? 굙녎 깩뙽녯꣬ ꅁ ꭨcꇗ?

꣒썄

7. 곛궼ꯡ곛떥

뻇ꗍ뵭닟

굙

2 x

3

+

3 x

2

+

kx

−

3 뭐

곛떥ꅁꭨ

kꇗ?

(2x b ax+ )( −5) 2

(

ax

+

b

)(2

x

+

3)

2 6x +2x c+ 깩뙽꓆슲(–2xꇏ6)2

꣒썄

8. ꞹꗾꖭꓨ꒽ꚡ깩뙽

뻇ꗍ뵭닟

깩뙽꓆슲

(–3x – 5)

2 깩뙽꓆슲(x – 1)(xꇏ1)(x2_ꇏ_1)(x4_ꇏ₁₎

꣒썄

9. ꖭꓨ깴꒽ꚡ깩뙽

뻇ꗍ뵭닟

깩뙽꓆슲

(3 – 5xꇏ2x

2

)(3ꇏ5x – 2x

2

)

#12 #13 #14 53

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Ꙩ뚵ꚡꪺ궼ꩫ - ꣒썄룑꩒

NOTE:

Q.꣏ꗎ엜볆엜뒫ꩫꪺꙮ덂결꛳?

NOTE:

Q1. ꑔ뚵궼ꕈꑔ뚵깩뙽ꯡꥼꖼ Ꙙ꣖Ꙑ쏾뚵ꭥꅁ라ꚳ둘뚵? Q2. 2 ꚸꙨ뚵ꚡ궼ꕈ 2 ꚸꙨ뚵ꚡ ꯡ라걏둘ꚸꙨ뚵ꚡ? ꓆슲(x2ꇏ25x – 23)(3x2– 25xꇏ23)ꇏ(–25xꇏ23)2

꣒썄

10. 엜볆엜뒫ꩫ

뻇ꗍ뵭닟

꓆슲

(2x

2

– 3x)(2x

2

– 3x – 6) – (2x

2

– 3xꇏ4)

2 Ꙣ(4x2_ꇏ_{7x – 7)(2x}2_{– 8x – 5) ꪺ깩뙽ꚡ꒤ꅁ} x2_{뚵ꪺꭙ볆결꛳}_?

꣒썄

11. 궼뽮ꪺꭙ볆

뻇ꗍ뵭닟

(3x

2

_{– 2xꇏ7)(2x}

2

_ꇏ

_{x – 6) 깩뙽ꯡꅁx}

3

_{뚵ꪺꭙ볆결꛳}

_?

Ꙣ(4x2ꇏ7x – 7)(2x2– 8x – 5) ꪺ깩뙽ꚡ꒤ꅁ ꙕ뚵ꭙ볆셠ꥍ결꛳?

꣒썄

12. ꭙ볆셠ꥍ

뻇ꗍ뵭닟

(3x

2

– 2xꇏ7)(2x

2

ꇏ

x – 6) 깩뙽ꯡꅁꙕ뚵ꭙ볆셠ꥍ결꛳?

#15 #16 #17

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Ꙩ뚵ꚡꪺ궼ꩫ - ꣒썄룑꩒

NOTE:

Q. ꑀ꿫꣓뮡ꅁ굮ꡄꡓꚳ꒽ꚡꕩ ꡄꪺꕼ쏤꟎궱뽮ꅁ라ꗎ꒰믲 ꓨꩫ? ꝑꗎꙨ뚵ꚡꫭꗜꛇꛢ뎡ꗷ궱뽮ꅃ

꣒썄

13. 궱뽮

뻇ꗍ뵭닟

ꝑꗎꙨ뚵ꚡꫭꗜꛇꛢ뎡ꗷ궱뽮ꅃ

8x – 3 2xꇏ1 3x xꇏ1 5xꇏ3 3xꇏ5 x – 1 #18 55

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뻇ꗍ뵭닟룑떪

Ꙩ뚵ꚡꪺ궼ꩫ

#6ꅇ–2x

4

#7ꅇ(1) –4x

3

+ 3x (2) –6x

4

+ 2x

3

– 4x

2

#8ꅇ–6x

3

+ 25x

2

– 4x

#9ꅇ–14x

2

– 50x + 26

#10ꅇ42x

3

+ 17x

2

+ 17x + 12

#11ꅇ–2x

5

+ 11x

3

+ 2x

2

+ 13x – 13

#12ꅇ–20

#13ꅇ4x

2

– 24x + 36

#14ꅇx

8

– 1

#15ꅇ3x

4

+ 50x

3

– 46x

2

#16ꅇ–90

#17ꅇ–44

#18ꅇ4x

2