因式分解：x²-2xy-3y²+8y-8x

假设能分解为x²-2xy-3y²+8y-8x=(x+my+n)(x+py)因(x+my+n)(x+py)=x²+(m+p)xy+mpy²+npy+nx待定系数有n=-8np=8,则p=-1mp=-3,则m=3m+p=-2,则p=-5（与p=-1不符）所以x²-2xy-3y²+8y-8x不能...