4x＾2-4xy-3y＾2-4x+10y-3
=4x＾2-6xy+2xy-3y＾2+2x -6x+y+9y-3
=(4x＾2-6xy+2x)+(2xy-3y＾2+y)-(6x-9y+3)
=2x(2x-3y+1)+y(2x-3y+1)-3(2x-3y+1)
=(2x-3y+1)(2x+y-3)