a: =(2x-3y)^2-4(2x-3y)

=(2x-3y)(2x-3y-4)

b: =3x^2+21x-x-7

=(x+7)(3x-1)

c: =(3x-1)^4+2(3x-1)^2+1

=[(3x-1)^2+1]^2

d: =2x^3-2x^2-x^2+x+x-1

=(x-1)(2x^2-x+1)

Bài 1:

\(=\left(3x-1\right)^2-9y^2\)

=(3x-1-3y)(3x-1+3y)

=(3x-1-3y)(3x-1+3y)
Tham khảo ạ

a) = (x - 2)² - y²

= (x - 2 - y)(x + 2 + y)

b) = (x^2 + 6x + 9) - (2y)^2

= (x + 3)² - (2y)²

= (x - 2y + 3)(x + 2y + 3)

c) = (x - 3y)² - 6²

= (x - 3y - 6)(x - 3y + 6)

4x² - 9y² + 4x - 6y

= (2x - 3y)(2x + 3y) + 2(2x - 3y)

= (2x - 3y)(2x + 3y + 2)

\(4x^2-9y^2+4x-6y\)

\(=\left(4x^2+4x+1\right)-\left(9y^2+6y+1\right)\)

\(=\left(2x+1\right)^2-\left(3y+1\right)^2\)

\(=\left(2x+1-3y-1\right)\left(2x+1+3y+1\right)\)

\(=\left(2x-3y\right)\left(2x+3y+2\right)\)

b. 5x + 5y - 3x - 3y

= (5x - 3x) + (5y - 3y)

= 2x + 2y

= 2(x + y)

Dạ e cảm ơn, e bt làm r, h còn mỗi câu a thôi ạ

=4x^2+2xy-18xy-9y^2

=2x(2x+y)-2y(2x+y)

=2(x-y)(2x+y)

4x^2+2xy-18xy-9y^2

=2x(2x+y)-9y(2x+y)

=(2x-9y)(2x+y)

Sorry bài trên mình làm sai 

\(x^4+6x^3+13x^2+12x+4\)

\(=x^4+x^3+5x^3+5x^2+8x^2+8x+4x+4\)

\(=x^3\left(x+1\right)+5x^2\left(x+1\right)+8x\left(x+1\right)+4\left(x+1\right)\)

\(=\left(x+1\right)\left(x^3+5x^2+8x+4\right)\)

\(=\left(x+1\right)\left(x^3+x^2+4x^2+4x+4x+4\right)\)

\(=\left(x+1\right)\left[x^2\left(x+1\right)+4x\left(x+1\right)+4\left(x+1\right)\right]\)

\(=\left(x+1\right)^2\left(x+2\right)^2\)

Em xem lại đề nha

em nghĩ đề cũng sai nên mới lên đây hỏi ạ :>

\(-4x^2+12xy-9y^2+25=25-\left(2x-3y\right)^2=\left(5-2x+3y\right)\left(5+2x-3y\right)\)

\(-4x^2+12xy-9y^2+25\)

\(=25-\left(4x^2-12xy+9y^2\right)\)

\(=25-\left(2x-3\right)^2\)

\(=\left(5+2x-3\right)\left(5-2x+3\right)\)

a: =(x^2-x+1)(x^2+x+1)

b: =x^2-6xy+9y^2=(x-3y)^2

c: =5x(x^2-2xy+y^2)

=5x(x-y)^2

d: =(x-3)^2

e: =(2y-z)(4x+7y)

a)HĐT:(x^2+1-x)(x^2+1+x)

b)=x^2-2.x.3y+(3y)^2

c)=5x(x^2-2xy+y^2)

=5x(x-y)^2

d)x^2-2.3.x+3^2

=(x-3)^2

e)(2y-z)+7y(2y-z)

=(2y-z)(1+7y)