6x^2-7xy-3y^2-x+7y-2
=6x^2-(7y+1)x-(3y^2-7y+2)
=6x^2-(7y+1)x-(y-2)(3y-1)
=[2x-(3y-1)][3x+(y-2)]
=(2x-3y+1)(3x+y-2)