已知x²=2y 3,y²=2x 3,则x三次方-4xy y三次方的值是
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x=log2(y)则X1+2X2+3X3=log2(y1)+2log2(y2)+3log2(y3)=log2(y1)+log2(y2^2)+log2(y3^3)=log2(y1y2^2y3^3)=1所
1/x严格减函数,y=-1/x严格增函数.当0
∵y=-2/x在(负无穷,0)上是增函数∴当y1>y2>y3>0时,0>x1>x2>x3选C
原式分解因式得x^3y^3(2x-y)=(xy)^3(2x-y)=8/3.(x^3表示x的3次方)
v已知ax3=by3=cz3且1/x+1/y+1/z=1求证(ax2+by2+cz2)1/3=a1/3+b1/3+c1/3令ax^3=by^3=cz^3=k,则:a=k/x^3、b=k/y^3、c=k
因为:X3-Y3-Z3=3XYZ所以:X3+(-Y)3+(-Z)3-3X(-Y)(-Z)=0(X-Y-Z)(X2+Y2+Z2+XY+XZ-YZ)=0所以:1.X-Y-Z=02.X2+Y2+Z2+XY+
∵(x+y+z)(x²+y²+z²)=x³+y³+z³+x²(y+z)+y²(x+z)+z²(x+y)∴1*2
(2x3-3x2y-2xy2)-(x3-2xy2+y3)+(-x3+3x2y-y3)=2x3-3x2y-2xy2-x3+2xy2-y3-x3+3x2y-y3=-2y3=-2×(-1)3=2.因为化简的
如果你的X2是x的平方,X3是x的三次方那么答案是:-(x-y+z)*(x-y-z)*(x+y-z)
y^2=x^3-3x^2+2xx^2=y^3-3y^2+2y两式相减得:y^2-x^2=(x^3-y^3)-3(x^2-y^2)+2(x-y)(x-y)(x^2+xy+y^2-2x-2y+2)=0所以
设x+3y3=2y+3z4=2z+2x5=k,则有:x+3y=3k2y+3z=4k2z+2x=5k,解得x=32ky=12kz=k;因此x:y:z=3:1:2.
∵k>0∴y=k/x的图象在一、三象限由图像可知,当A的横坐标为-2,B的横坐标为-1,C的横坐标为3的时候则y3>y1>y2
原式=x3+3x2y-5xy2+6x3+1-2x3+y3+2xy2+x2y+2-4x2y-7x3-y3+4xy2+1=-2x3+xy2+4,由于y为偶次幂,故误把“x=3,y=-1”写成“x=3,y=
A-B=(x3+2y3-xy2)-(﹣y3+x3+2xy2)=x³+2y³-xy²+y³-x³-2xy²=3y³-3xy²
(x+2)²+|y-1|=0平方数与绝对值都是非负数两个非负数的和为0,那么这两个数都是0x+2=0y-1=0解得:x=-2,y=1x³+3x²y+3xy²+y
条件应为x与y不等.这样的话,x²-y²=x³-y³(x+y)(x-y)=(x-y)(x²+xy+y²)∵x-y≠0∴x+y=x²
a^3+2^3=(a+2)(a^2-2a+4)(3a)^3-1=(3a-1)(9a^2+3a+1)