8x³ 26xy
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x-xy=8(1)xy-y=-9(2)则有(1)-(2):X-XY-XY+Y=X+Y-2XY=8-(-9)=17
再问:该方法此处计算是错的,应该为,接下来的都不对了再答:那就从那步开始吧x+y=xy-8若x,y大于0xy-8=x+y≥2√xyxy-8≥2√xyxy-2√xy-8≥0(√xy-4)(√xy+2)≥
8(x平方-2y平方)-x(7x+y)+xy=8x平方-16y平方-7x平方-xy+xy=x平方-4y平方=(x-2y)(x+2y)手机提问的朋友在客户端右上角评价点【满意】即可.再问:太棒了!连我这
对.前提是x不等于y
-2x平方-12xy平方+8xy立方=-2x(x+6y平方-4y立方)(2a+3分之1b)(3分之1b-2分之1a)=9分之1b²-a²+2分之1a
X²-XY+2X=O提公因数X即X(X-Y+2)=0则X=0或X-Y+2=0假如X=0那么代入X²-2XY+Y+8=0解得Y=﹣8即X=0Y=﹣8假如X≠0则X-Y+2=0即X=Y
(8xy-3x平方)-5xy-2(3xy-2x平方)=8xy-3x²-5xy-6xy+4x²=x²-3xy=4+6=10
(x^2+3x+2)(3+8x+4x^2)-90=(x+2)(x+1)(2x+1)(2x+3)-90=(x+2)(2x+1)(x+1)(2x+3)-90=(2x^2+5x+2)(2x^2+5x+3)-
-4x²y-8xy²+2x²y-3xy²=-2x²y-11xy²=-xy(2x+11y)
1、已知2x²+xy=10,3y²+2xy=6,求4x²+8xy+9y²的值为?分析:通过观察,可以把8xy拆成2xy+6xy,分别于剩余的两项组合,并提取公因
你确定没写错题目?后面的式子一约就变成前面的式子了,答案也是8/xy再问:怎么个约法?再答:y/xyyy约掉剩下1/x
3x-2xy-8-2x+6xy-x²+6=-x²+(-2+6)xy+(3-2)x+(-8+6)=-x²+4xy+x-2-x²+2xy-y²-3x
设X=kY.kY^2/(3k+2)Y=1/8kY^2/((2k+3)Y=1/7由上式得:3k+2=8kY,2k+3=7kY所以2/(8Y-3)=3/(7Y-2)所以Y=1/2,X=1
(5xy+4x+7y)+(6x-3xy)-(4xy-3y)=5xy+4x+7y+6x-3xy-4xy+3y=(5xy-3xy-4xy)+(4x+6x)+(7y+3y)=-2xy+10x+10y=-2x
4x²+7xy-y²=04(x/y)²+7(x/y)-1=0∴x/y=(-7±√65)/8
那9是负的吗~如果不是等于负1,如果是负九等于十七~用第一个等式减第二个等式
2x²-12xy²+8xy³=2x(x-6y²+4y³)
由xy+x=16,得x=16/(y+1)代入xy-x=8,得16y/(y+1)-16/(y+1)=8=>16(y-1)/(y+1)=8=>(y-1)/(y+1)=1/2移项,通分得y-3/2(y+1)
(1)-3X^-2XY-8XY-(-5Y^2)-2X^2-Y^2=-3x^2-2xy-8xy+5y^2-2x^2-y^2=-5x^2-10xy+4y^2(2)3(-2+3X-X^2)-(4-3X+X^
x平方-8y平方-2xy-2x+26y-15=(x+2y)(x-4y)-2x+26y-15=(x+2y)(x-4y)+3(x+2y)-5(x-4y+3)=(x+2y)(x-4y+3)-5(x-4y+3