先化解在求值x分之x平方-y-x-1
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/20 10:33:09
(x-y)分之(x²+y²)+(y-x)分之(2x-y),其中x=3+√2,y=3-√2=(x²+y²)/(x-y)-(2x-y)/(x-y)=(x²
[1/(x-y)-1/(x+y)]÷2y/(x^2-2xy+y^2)=[(x+y)/(x+y)(x-y)-(x-y)/(x+y)(x-y)]÷2y/(x-y)^2=[(x+y-x+y)/(x+y)(x
原式=(3x²+3x-x²+x)/(x+1)(x-1)*x(x²-1)/x²(x²-4)=(2x²+4x)/(x+1)(x-1)*(x+1)
(xy-x的平方)除以xy分之x的平方-2xy+y的平方乘x的平方分之x-y=x(y-x)*xy/(x-y)²*(x-y)/x²=-y再问:不好意思,打错了(xy-y的平方)除以x
原式=17x^2-8x^2-5x-4x^2-x十3-5x^2十6x-1-3=17x^2-17x^2-6x十6x-1=-1与x的值无关所以无论x取何值代数式值恒为-1
2x²-3xy+y²-2xy-2x²+5xy-2y+1=2xy-2xy-2y+y²+1=(y-1)²=(-1-1)²=4
y的平方-xy分之(x+y)的平方÷{-(x-y)的平方分之y的平方+xy}=(x+y)²/[y(y-x)]÷[-y(y+x)/(x-y)²]=(x+y)²/[y(x-y
2xy²-x²y-3分之1(-3x²y-6xy²)=2xy²-x²y+xy²+2x²y=3xy²+x²
x²-4y²分之x+2y=[(x-2y)(x+2y)]分之x+2y=x-2y分之1=5-2*3.5=-2
x²-2x2x-1————÷(x-1-———)x²-1x+1x²-2x(x+1)(x-1)-(2x-1)=————÷————————x²-1x+1x²
/>原式=[(x²-2xy+y²)/(x²-xy)]÷(x/y-y/x)={(x-y)²/[x(x-y)]}÷[(x²-y²)/(xy)]=
原式=x²/(x-1)×x(x-1)/(x-1)²=x³当x=2时原式=2³=8再问:x²-1/(x²-1)chux²-x/x
(2x+y)(2x-y)(4x平方+y平方)=(4x^2-y^2)(4x^2+y^2)=16x^4-y^4=16*(1/2)^4-(1/3)^4=80/81
3a(2a²-4a+3)-2a²(3a+4)=6a³-12a²+9a-6a³-8a²=9a-20a²=a(9-20a)=-2(9+
3x²-x-1=0x+1=3x²(2x-x+1分子x2-2x)÷x2-4x分子x2-16=[2x(x+1)-x²+2x]/(x+1)÷(x+4)(x-4)/x(x-4)=
|x+1|+(y+2分之1)的平方=0x+1=0y+2分之1=0x=-1y=-2分之13X-2y-[-4x+(y+3x)]-(2x-3y)=3X-2y-(-4x+y+3x)-2x+3y=3X-2y+4
2(x+x²y)-3分之2(6x²y+3x)-y=2x+2x²y-4x²y-2x-y=-2x²y-y=-2×1²×3-3=-9
3x平方*(2y-x)-3y*(2x平方-y)=6x^2y-3x^3-6x^2y+3y3=-3(x^3-y^3),当x=1/3,y=-1/3得到原式=3*(1/27+1/27)=2/9