用因式分解法解方程:2X²+XY-6Y²=0

问题描述:

用因式分解法解方程:2X²+XY-6Y²=0

2X²+XY-6Y²=0,
(2x-3y)(x+2y)=0
2x-3y=0, 或x+2y=0
即x=3y/2, x=-2y

(2x+3y)(x-y)=0

2X²+XY-6Y²=0可分解为
(2x-3y)(x+2y)=0
则2x-3y=0或x+2y=0
解得x=3/2y 或x=-2y

(2x-3)(x+2)=0

用十字交叉发:(2x+3y)(x-y)=0
解得x=-3y/2或x=y


2X²+XY-6Y²=0
(2x-3y)(x+2y)=0
y=2x/3或y=-x/2

根据十字相乘法得(x+2y)(2x-y)=0所以x+2y=0,2x-3y=0

2X²+XY-6Y²=0
(2x-3y)(x+2y)=0
2x-3y=0或x+2y=0
x=3/2y或x=-2y

因式分解的结果是(2X+3Y)(X-2Y)=0,解的X=-2\3或X=2