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


