2.1
a. 3x2y - 2xy2
= xy(3x - 2y)
b. x2 - y2 - 4x + 4
= x2 - 4x + 4 - y2
= (x - 2)2 - y2
= (x - 2 - y)(x - 2 + y)
2.1
a) \(3x^2y-2xy=xy\left(3x-2\right)\)
b) \(x^2-y^2-4x+4=\left(x^2-4x+4\right)-y^2\)
\(=\left(x-2\right)^2-y^2=\left(x-2-y\right)\left(x-2+y\right)\)
2.2
\(3x\left(x-2\right)-2+x=0\)
\(\Rightarrow3x\left(x-2\right)-\left(x-2\right)=0\)
\(\Rightarrow\left(x-2\right)\left(3x-1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{1}{3}\end{matrix}\right.\)