Ok

Mình không giảnh để trả lời câu hỏi này 

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)

\(12y-9x^2+36-3x^2y\)

\(=\left(36-9x^2\right)-\left(3x^2y-12y\right)\)

\(=-9\left(x^2-4\right)-3y\left(x^2-4\right)\)

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

=(−3)(x−2)(x+2)(3+y)

3x³ + 6x² + 3x - 12xy² 

= 3x(x² + 2x + 1 - 4y²) 

= 3x[(x + 1)² - (2y)²]

= 3x(x + 1 + 2y)(x - 2y + 1)

\(3x^3+6x^2+3x-12xy^2\)

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

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

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

\(a.3x^2-12xy=3x\left(x-4y\right)\)

\(b.x^2+7x-2\left(x+7\right)=x\left(x+7\right)-2\left(x+7\right)=\left(x-2\right)\left(x+7\right)\)

\(c.8x^3-8x^2+2x=2x\left(4x^2-4+1\right)=2x\left(2x-1\right)^2\)

\(d.x^2-y^2+12y-36=x^2-\left(y-6\right)^2=\left(x-y-6\right)\left(x-y+6\right)\)

Bài làm

a) 3x² - 12xy

= 3x( x - 4y )

b) x² + 7x - 2( x + 7 )

= x( x + 7 ) - 2( x + 7 )

= ( x + 7 )( x - 2 )

c) 8x³ - 8x² + 2x

= 2x( 4x² - 4x + 1 )

= 2x( 2x - 1 )² 

d) x² - y² + 12y - 36 

= x² - ( y² - 12y + 36 )

= x² - ( y² - 2.y.6 + 6² )

= x² - ( y - 6 )² 

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

# Học tốt #

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

\(8x^2y-18y\)

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

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

\(3x^3+6x^2+3x-12xy^2\)

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

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

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