Question

[duka]

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

Answer 1

[Nguyễn Lê Phước Thịnh]

d: \(x\left(x^2-1\right)+3\left(x^2-1\right)\)

\(=\left(x-1\right)\left(x+1\right)\left(x+3\right)\)

e: \(x^2-10x+25=\left(x-5\right)^2\)

g: \(x^2-64=\left(x-8\right)\left(x+8\right)\)

h: \(\left(x+y\right)^2-\left(x^2-y^2\right)\)

\(=\left(x+y\right)\left(x+y-x+y\right)\)

\(=2y\left(x+y\right)\)

i: \(5x^2+5xy-x-y\)

\(=5x\left(x+y\right)-\left(x+y\right)\)

\(=\left(x+y\right)\left(5x-1\right)\)

k: \(x^2+2xy+y^2-25=\left(x+y-5\right)\left(x+y+5\right)\)

l: \(2xy-x^2-y^2+16\)

\(=-\left(x^2-2xy+y^2-16\right)\)

\(=-\left(x-y-4\right)\left(x-y+4\right)\)

Answer 2

[Nguyễn Lê Phước Thịnh]

a: \(5x-15y=5\left(x-3y\right)\)

b: \(5x^2y^2+15x^2y+30xy^2=5xy\left(xy+3x+6y\right)\)

c: \(x^3-2x^2y+xy^2-9x\)

\(=x\left(x^2-9-2xy+y^2\right)\)

\(=x\left(x-y-3\right)\left(x-y+3\right)\)