(6x-1)(2x-1)(3x-1)(x-1)+x =[(2x-1)(3x-1)][(6x-1)(x-1)]+x =(6x-5x+1)(6x-7x+1)+x =[(6x-6x+1)+x][(6x-6x+1)-x]+x =(6x-6x+1)-x+x =(6x-6x+1)