a.
\(=x^2\left(x-1\right)-\left(x-1\right)=\left(x-1\right)\left(x^2-1\right)=\left(x-1\right)\left(x+1\right)\left(x-1\right)\)
a, x^2(x-1) - (x-1)
= (x-1)(x^2-1)
a) \(x^2\left(x-1\right)-x+1\)
\(=x^2\left(x-1\right)-\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2-1\right)\)
\(=\left(x-1\right)^2\left(x+1\right)\)
b) \(6x\left(x-3\right)+9-3x^2\)
\(=6x^2-18x+9-3x^2\)
\(=3x^2-18x+9\)
\(=3\left(x^2-6x+3\right)\)