x²-Y²-x-5y-6分解因式很清晰了

x²-Y²-x-5y-6分解因式
很清晰了

原式=x²-Y²-x-5y-6
=(x²-x+1/4)-(Y²+5y+25/4)
=(x-1/2)²-（Y+5/2)²
=[(x-1/2)+(Y+5/2)][(x-1/2)-(Y+5/2)]
=(x+Y+2)(x-Y-3)

x²-Y²-x-5y-6
=(x＋y)(x－y)-x－5y-6
=(x＋y＋2)(x－y－3)
十字相乘
x＋y 2
x－y ﹣3