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

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

=3(x²-y²-4x-4y)

=3.(x+y).(x-y-4)

b: \(x^2-6x+xy-6y\)

\(=x\left(x-6\right)+y\left(x-6\right)\)

\(=\left(x-6\right)\left(x+y\right)\)

c: \(2x^2+2xy-x-y\)

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

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

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

Đề sai òi       

Lời giải:

1. $xy+xz-2y-2z=(xy+xz)-(2y+2z)$

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

2. $x^2-6xy+9y^2)-25z^2$

$=(x-3y)^2-(5z)^2=(x-3y-5z)(x-3y+5z)$
3.

$3x^2-3y^2-12x+12y=(3x^2-3y^2)-(12x-12y)=3(x^2-y^2)-12(x-y)=3(x-y)(x+y)-12(x-y)=3(x-y)(x+y-4)$

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

=3[(x-y)(x+y)-4(x-y)]

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

b: \(=4x\left(x^2+y^2+2xy-16\right)\)

\(=4x\left[\left(x+y\right)^2-16\right]\)

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

c: \(=\left(x+4\right)^2-y^2=\left(x+4+y\right)\left(x+4-y\right)\)

d: \(=\left(x^2-1\right)\left(x^2-9\right)=\left(x-1\right)\left(x-3\right)\left(x+1\right)\left(x+3\right)\)

Ta có: 3x² - 3y² - 12x + 12y

= (3x² - 3y²) - (12x - 12y)

= 3.(x² - y²) - 12.(x - y)

= 3.(x - y).(x + y) - 4.3(x - y)

= 3.(x - y).(x + y - 4)

@Nguyễn Việt Lâm thầy giúp em với !

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

\(=\left(x-2\right)^2-y^2\)

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

giải thích chi tiết giúp e ạ.e cảm ơn

\(3x^2-3y^2-12x-12y\)

\(=3\left(x+y\right)\left(x-y\right)-12\left(x+y\right)\)

\(=\left(x+y\right)\left(3x-3y-12\right)\)