a)\(ax-2x-a^2+2a\)
\(=\left(ax-2x\right)-\left(a^2-2a\right)\)
\(=x\left(a-2\right)-a\left(a-2\right)\)
\(=\left(x-a\right)\left(a-2\right)\)
b)\(x^2+x-ax-a\)
\(=\left(x^2+x\right)-\left(ax+a\right)\)
\(=x\left(x+1\right)-a\left(x+1\right)\)
\(=\left(x-a\right)\left(x+1\right)\)
c)\(2x^2+4ax+x+2a\)
\(=\left(2x^2+4ax\right)+\left(x+2a\right)\)
\(=2x\left(x+2a\right)+\left(x+2a\right)\)
\(=\left(2x+1\right)\left(x+2a\right)\)
d)\(3x^2-3y^2-2\left(x-y\right)^2\)
\(=3\left(x^2-y^2\right)-2\left(x-y\right)^2\)
\(=3\left(x-y\right)\left(x+y\right)-2\left(x-y\right)^2\)
\(=\left(x-y\right)\left(3\left(x+y\right)-2\left(x-y\right)\right)\)
\(=\left(x-y\right)\left(3x+3y-2x+2y\right)\)
\(=\left(x-y\right)\left(x+5y\right)\)