4x^2+2xy-2y^2+4x+7y-3
问题描述：
4x^2+2xy-2y^2+4x+7y-3
分解因式:4X^2+2XY-2Y^2+4X+7Y-3
=4X^2+(2XY+4X)-(2Y^2-7Y+3)
=4X^2+(2Y+4)X-(2Y-1)(Y-3)
=(2X+2Y-1)(2X-Y+3)
其中=4X^2+(2Y+4)X-(2Y-1)(Y-3)之后该怎么做?
答
4X^2+2XY-2Y^2+4X+7Y-3
=4X^2+(2XY+4X)-(2Y^2-7Y+3)
=4X^2+(2Y+4)X-(2Y-1)(Y-3)(十字相乘)
2X 2Y-1
2X -(Y-3)
=(2X+2Y-1)(2X-Y+3)