a/ \(x^2-3x+xy-3y\)
\(=x\left(x-3\right)+y\left(x-3\right)\)
\(=\left(x+y\right)\left(x-3\right)\)
Vậy...
b/ \(x^4-9x^3+x^2-9x\)
\(=x^3\left(x-9\right)+x\left(x-9\right)\)
\(=\left(x-9\right)\left(x^3+x\right)\)
\(=x\left(x-9\right)\left(x^2+1\right)\)
Vậy...
c/ \(x^3-4x^2-9x+36\)
\(=x^2\left(x-4\right)-9\left(x-4\right)\)
\(=\left(x^2-9\right)\left(x-4\right)\)
\(=\left(x-3\right)\left(x+3\right)\left(x-4\right)\)
Vậy...
d/ \(x^3+2x^2+2x+1\)
\(=\left(x^3+1\right)+\left(2x^2+2x\right)\)
\(=\left(x+1\right)\left(x^2-x+1\right)+2x\left(x+1\right)\)
\(=\left(x+1\right)\left(x^2+x+1\right)\)
Vậy...
f/ \(x^3-4x^2+12x-27\)
\(=\left(x^3-27\right)-\left(4x^2-12x\right)\)
\(=\left(x-3\right)\left(x^2+3x+9\right)-4x\left(x-3\right)\)
\(=\left(x-3\right)\left(x^2-x+9\right)\)
Vậy..
chữ mình nó không được đẹp cho lắm, thông cảm
