y的平方减2y减3等于0 用因式分解法解方程-搜答案-智慧作业帮

x³－2x²y＋xy²=x(x²－2xy＋y²)=x(x－y)²

x^2+2xy+y^2=25===>(x+y)^2=5^2===>x+y=±5(x-y)^2-3x+3y+2=0===>(x-y)^2-3(x-y)+2=0===>[(x-y)-1]*[(x-y)-2

求根法：x^2+xy-2y^2+2x+7y-3=x^2+x(y+2)-2y^2+7y-3,△（x)=(y+2)^2-4(-2y^2+7y-3)=9y^2-24y+16=(3y-4)^2,x1=[-(y

解x²-5=x²-(√5)²=(x-√5)(x+√5)x²-4y²=x²-(2y)²=(x-2y)(x+2y)

原式=3y（y-2）3y=0或y-2=0解得y=0或y=2

x^2-y^2+2y-1=x^2-(y-1)^2=(x+y-1)(x-y+1)

-y∧2-2y+3＝0y∧2+2y-3＝0y∧2+2y+1-4＝0（y+1）∧2＝4y+1＝±2y1＝1,y2＝-3

12x^2-3y^2=3(4x^2-y^2)提取最大公因式"3"=3(2x+y)(2x-y)逆用平方差公式进行因式分解

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

25x^2-16y^2=(5x)^2-(4y)^2=(5x+4y)(5x-4y)

平方差原式=(5x+4y)(5x-4y)

2x的平方减8Y的平方=2(x²-4y²)=2(x+2y)(x-2y)

x的平方减2y减y的平方减1=x^2-(y^2+2y+1)=x^2-(y+1)^2=(x+y+1)(x-y-1)

x²-4y²=x²-（2y）²=（x+2y）（x-2y）这里用到了平方差公式.很高兴为您解答,祝你学习进步!如果我的回答对你有帮助,请及时选为满意答案,谢谢~~

2x^2-4xy+2y^2=2(x^2-2xy+y^2)=2(x-y)^2

（x-y+z）(x-y-z)

3y-6y=0y-2y=0y(y-2)=0y1=0y2-2=0y2=2所以y1=0;y2=2