\(9x^2-6x^2-3\)

\(=3x^2-3\)

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

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

\(3x^2-6x+9x^2=12x^2-6x=6x\left(2x-1\right)\)

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

\(x^2\left(x-2\right)-4x\left(x-2\right)+\left(x-2\right)\)

vậy................

\(\left(x^3-2x^2\right)-\left(4x^2-8x\right)+\left(x-2\right)\)

\(x^2\left(x-2\right)-4x\left(x-2\right)+\left(x-2\right)\)

Vậy ........

\(-9x^2+6x+y^2-1\)

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

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

1. \(x^3+2x^2-6x-27=\left(x-3\right)\left(x^2+5x+9\right)\)

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

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

3. \(12x^3+4x^2-27x-9=4x^2\left(3x+1\right)-9\left(3x+1\right)\)

\(=\left(3x+1\right)\left(x^2-\dfrac{9}{4}\right)=\left(x+\dfrac{1}{3}\right)\left(x+\dfrac{3}{2}\right)\left(x-\dfrac{3}{2}\right)\)

1) Ta có: \(x^3+2x^2-6x-27\)

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

\(=\left(x-3\right)\left(x^2+5x+9\right)\)

2: Ta có: \(9x^2+6x-4y^2-4y\)

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

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

\(x^3+9x^2+6x-16\)

\(=x^3+x^2-2x+8x^2+8x-16\)

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

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

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

\(=\left[x\left(x-1\right)+2\left(x-1\right)\right]\left(x+8\right)\)

\(=\left(x-1\right)\left(x+2\right)\left(x+8\right)\)

\(x^3+6x^2+9x=x\left(x^2+6x+9\right)=x\left(x+3\right)^2\)

\(x^3+6x^2+9x\)

\(=x\left(x^2+6x+9\right)\)

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

a) \(27x^3+27x^2+9x+1=\left(3x+1\right)^3\)

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

c) \(-8+12x-6x^2+x^3=\left(x-2\right)^3\)

Ta có: \(2x^4+6x^3+9x^2+6x+1=2x^4+2x^3+4x^3+4x^2+5x^2+5x+x+1\)

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

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

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