已知y=1 2x x-5 2-搜答案-搜搜考试网

(x-y)(x+y)(xx-yy)=?

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

X:Y:Z=1:2:3因为：14(XX+YY+ZZ)=(X+2Y+3Z)^214(XX+YY+ZZ)-(X+2Y+3Z)^2=013X^2+10Y^2+5Z^2-4XY-6XZ-12YZ=0(4X^2

(x²+xy-12)²+(xy-2y²-1)²=0由于平方数都大于或等于0,所以上式成立的前提是：(x²+xy-12)²=0,即：x&sup

y=x²+kx-12的图像向右平移4个单位y=(x-4)²+k(x-4)-120=16-4k-12k=1

x-z=(x-y)+(y-z)=5+4=9(x-y)²=x²-2xy+y²=25(y-z)²=y²-2yz+z²=16(x-z)²

函数y=xx

∵x＞0∴y=xx2+x+1=1x+1+1x又∵x+1x≥2x•1x＝2∴1y＝x+1x+1≥ 3，当且仅当x=1时等号成立∴0＜y≤13，即函数的值域为(0，13]故答案为：(0，13]

已知y＝xx

根据题意得，xx2−x÷x2−1x2−2x+1−2x+1＝13，xx(x−1)×(x−1)2(x−1)(x+1)-2x+1=13，-1x+1=13，解得x=-4，经检验x=-4是原方程的根；∴原方程的

已知xx

由xx2+x+1＝13整理变形，转化为x+1x＝2，分式x2x4+x2+1=13．故答案为13．

XX+YY-4X-6Y+13=(XX-2X+4)+(YY-6Y+9)=(X-2)(X-2)+(Y-3)(Y-3)=0所以(X-2)的平方和(Y-3)的平方都等于0所以X=2,Y=3所以3X+4Y=18

已知函数y＝2xx

∵y＝2xx2+1−3，∴（y+3）x2-2x+y+3=0当y≠-3时，∵x∈R，∴4-4（y+3）2≥0∴-4≤y＜-3或-3＜y≤2当y=-3时，x=0∴A=[-4，-2]…（4分）若k=0时，则

x+y=5,xy=-3,则x^2y+xy^2=xy(x+y)=-3*5=-15

2/9再问：过程，谢谢再答：由题目得y/x=2/3xy/xx+yy-yy/xx-yy=y/x-(y/x)²=2/3-4/9=2/9

x2+y2-z2+2xy/x2-y2+z2-2xz=(x+y)2-z2/(x-z)2-y2=(x+y-z)(x+y+z)/(x-y-z)(x-z+y)=(x+y+z)/(x-y-z)然后就是代入了

xx+yy+4x-6y+13=0整理得：(x+2)^2+(y-3)^2=0那么只有(x+2)=0(y-3)=0x=-2y=3(x^2-2x)/(x^2+3y^2)=(4+4)/(4+3*9)=8/31

x^2+x-x^2-y=3x-y=3(x-y)^2=9x^2+y^2-2xy=9(x^2+y^2)/2-xy=9/2

(x+y)(x+y)=25x^2+2xy+y^2=25……(1)(x-y)(x-y)=9x^2-2xy+y^2=9……（2）（1）+（2）得：2x^2+2y^2=34x^2+y^2=17(1)-(2)

x^2-2x+y^2+6y+10=0(x-1)^2+(y+3)^2=0所以x=1,y=-3x+y=-2x^2表示x的平方

XX+YY+4X-6Y+13=0(X+2)²+(Y-3)²=0X+2=0Y-3=0X=-2Y=3X的Y次方=-8

方程组：X-Y=2……①X^2-Y^2=12……②②÷①得X+Y=6……③①+③得：2X=8,X=4,把X=4代入③得：Y=2,X=4Y=2