x²-3xy-10y²+x+9y-2
=(x-5y)(x+2y)-x+5y+2x+4y-2
=(x-5y)(x+2y)-(x-5y)+2x+4y-2
=(x-5y)(x+2y-1)+2(x+2y-1)
=(x+2y-1)(x-5y+2)