a, \(\left(3x-2-x-3\right)\left(3x-2+x+3\right)=0\Leftrightarrow\left(2x-5\right)\left(4x+1\right)=0\Leftrightarrow x=\dfrac{5}{2};x=-\dfrac{1}{4}\)
b, \(x^2-3x+2x-x^2-2+x+5x=13\Leftrightarrow5x=15\Leftrightarrow x=3\)
c, \(2x^2+4x-x^2-6x+1=0\Leftrightarrow x^2-2x+1=0\Leftrightarrow\left(x-1\right)^2=0\Leftrightarrow x=1\)