3x² - 3xy

= 3x ( x - y )

`3x-3y+a(x-y)`

`=3(x-y)+a(x-y)`

`=(x-y)(a+3)`

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

`3x^2 - 6x`

`= 3x.x-3x.2`

`=3x(x-2)`

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

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

\(3x\left(x-5y\right)-2y\left(5y-x\right)\)

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

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

\(3x\left(x-7\right)+2xy-14y\)

\(=3x\left(x-7\right)+2y\left(x-7\right)\)

\(=\left(x-7\right)\left(3x+2y\right)\)

#\(Toru\)

bạn có thể ghi rõ lại được ko ạ, bạn có thể thay dấu nhân bằng dấu chấm

Ta có: \(3x\left(x-1\right)^2-5x^2\left(x-1\right)-7\left(x-1\right)\)

\(=\left(x-1\right)\left[3x\left(x-1\right)-5x^2-7\right]\)

\(=\left(x-1\right)\left(3x^2-3x-5x^2-7\right)\)

\(=\left(x-1\right)\left(-2x^2-3x-7\right)\)

(x-1)(3x-4x)

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

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

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

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

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

\(4x^2+8xy+3x+6y\)

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

\(=7\left(x+2y\right)\)

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