Thu gọn: x2 – 4 – (x + 2)2

Bài 1. Thu gọn:

a) x2 – 4 – (x + 2)2

b) (x + 2)(x – 2) – (x – 3)(x + 1)

 

c) (x – 2)(x + 2) – (x – 2)(x + 5)

d) (6x + 1)2 + (6x – 1)2 – 2(6x + 1)(6x – 1)

 

e) 7a(3a – 5) + (2a -3)(4a + 1) – (6a – 2)2

g) (5y – 3)(5y + 3) – (5y – 4)2

 

h) (3x + 1)3 – (1 – 2x)3

i) (2x + 1)2 + 2(4x2 – 1) + (2x – 1)2 

 

Bài 2. Phân tích đa thức thành nhân tử

a) 5x – 15y

b) 5x2y2 + 15x2y + 30xy2

 

c) x3 – 2x2y + xy2 – 9x

d) x(x2 – 1) + 3(x2 – 1)

 

e) x2 – 10x + 25

g) x2 – 64

 

h) (x + y)2 – (x2 – y2)

i) 5x2 + 5xy – x – y

 

k) x2 – 25 + y2 + 2xy

l) 2xy – x2 – y2 + 16

 

m) (x – 2)(x – 3) + (x – 2) - 1

n) 3(x – 1) + 5x( 1 – x)

 

p) 12y(2x – 5) + 6xy(5 – 2x)

q) ax – 2x – a2  + 2a

 

Bài 3. Phân tích đa thức thành nhân tử

a) a2 – b2 – 2a + 1

b) x2 – 2x – 4y2 – 4y

 

c) x2 + 4x – y2 + 4

d) x4 – 1

 

e) x4 + x3 + x2 + x

g) a2 + 2ab + b2 – ac - bc