x(x-1)-(x的平方-y)=-3,(y-x 2xy) 2-xy-搜答案-灵鹊做题网

不能分解了,别费劲了

（1）x的平方-y的平方+4x+4y=(x+y)(x-y)+4(x+y)=(x+y)(x-y+4)（2）x的平方*y的平方+1-x的平方-y的平方=x²y²-x²+1-y

(-1.5,0)

[2x的平方-(x+y)(x-y)][(-x-y)(y-x)+2y的平方]=[2x²-(x²-y²)][(x+y)(x-y)+2y²]=(2x²-x&

25(x-y)^2+10(y-x)+1=25(x-y)^2-10(x-y)+1={5(x-y)-1}^2=(5x-5y+1)^2

x²+y²-4x+1=0;(x-2)²+y²=3;所以半径r=√3,圆心：(2,0)1)设k=y/x;y=kx;代入原来方程,整理：（1+k²）x&s

(x+y)^2-4（x+y）+4=（x+y-2)^2

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

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

第一题应该是+1/4吧=(x+1/2)^2-y^2=(x+y+1/2)(x-y+1/2)2.(x+y-2)^2

X+Y=√（X平方+2XY+Y平方）

x/(x+y)(x--)^3=x/(x+y)(x--y)^3y/(y+x)(y--x)^2=y(x--y)/(x+y)(x--y)^3.

解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy

(x+y)的平方+2(x+y)+1=(x+y)²+2×(x+y)×1+1²=(x+y+1）²

x^2+y^2=(x+y)^2-2xy=(x+y)^2-2((x+y)^2-(x-y)^2)/4=1-2×(1-49)/4=25

（1-y+x分之y）÷y的平方-x的平方分之x=[(y+x-y)/(y+x)]÷x/(y²-x²)=x/(y+x)*[(y+x)(y-x)/x]=y-x

1.(2x-3y)^2-(y+3x)(3x-y)=4x^2-12xy+9y^2-(3x+y)(3x-y)=4x^2-12xy+9y^2-9x^2+y^2=10y^2-5x^2-12xy2.[(x-y)

首先知道这是x属于R,因为分母永远不等于0.然后把y化成(2y-1)x^2+(1-2y)x+3y-1=0不知道我有没有错,你自己化一下.这时二次方程,当然y成了系数,故此要是有实数解,必须使判别式大于

令x²+x=m原式=(2m+1)y+m(y²+1)=my²+(2m+1)y+m令原式=0△=(2m+1)²-4m²=4m+1=4x²+4x+

x-y分之2x的平方-y-x分之x的平方-4xy+x-y分之2y的平方-x的平方=2x/(x-y)-(x²-4xy)/(y-x)+(2y-x²)/(x-y)=(2x+x²