x*2 y*2 4x 3y 2=0
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由2(X+Y)3X+3Y=24得:2(X+Y)X+Y=8①;(X+Y/2X)XY/2Y=1得:X+Y=4②;由①、②得出Y=8(1-X),进入②知X=4/7;即Y=24/7
2/x+2/y=根号24(2y+2x)/xy=2√6x+y=xy√6x/y(x-y)-y/x(x-y)=1/(x-y)[(x/y-y/x)]=1/(x-y)[(x²-y²)/xy]
你的题目有点问题我这样做了x/{y(x-y)}-y/{x(x-y)}=(x平方-y平方)/{xy(x-y)}=(x+y)/xy2/x+2/y=2(x+y)/xy=根号24
Dx^y+x^-y=2根号2===>(x^y+x^-y)^2=8===>x^2y+x^-2y+2=8===>x^2y+x^-2y=6(x^y-x^-y)^2=x^2y+x^-2y-2=6-2=4==>
多项式2x3y2-3x2y3-5x4y+6xy4-5中,x的系数依次3,2,4,1,按x的降幂排列是-5x4y+2x3y2-3x2y3+6xy4-5.
化简得:9-12Y^2+6Y+4+12Y^2+4Y-10-10Y+X-Y+1=X-Y+4带入X、Y值得:=3
(x*x+y*y)(x*x+y*y)-4x*x*y*y=(x^4-2x^2y^2+y^4)=(x^2-y^2)^2=0x^2=y^2x/y=±1(x*x+5xy+y*y)/(x*x+2xy+y*y)=
∵(x+1)²+|y+2|=0∴要使等式成立,则x+1=0且y+2=0即x=-1,y=-2∴5xy-3/2x³y²-4xy+1/2y²x³-1/2xy
原式=8x2y2(x-3y).故多项式8x3y2-24x2y3提取公因式8x2y2后,另一个因式是(x-3y).
多项式的各项为x2y,-2x3y2,-3,4xy3,按字母x的升幂排列是-3+4xy3+x2y-2x3y2.故答案为-3+4xy3+x2y-2x3y2.
X^2表示平方X^2+4X+4+Y^2-2Y+1=0(X+2)^2+(Y-1)^2=0因为平方大于=0所以X+2=0Y-1=0X=-2Y=1X^2+Y^2=5
即(x-2y)²=0x-2y=0所以x=2y所以原式=(2x²+2xy-xy-y²)/(4x²-4xy+y²)=(2x²+xy-y²
由x²+y²-4x-10y+29=0得(x-2)²+(y-5)²=0所以x=2y=5所以x²y²+2x^3*y²+x^4*y&su
令a=2x-y,b=x+y用ab表示不等式,有4/3a-2/3b=01/3(a+b)
3xy2(x-x3y2-12x2y)=3x2y2-3x4y4-32x3y3,当xy=-1时,原式=3×(-1)2-3×(-1)4-32×(-1)3=32.
(y1,y2,y3)'=[2-2-3][111][13-1](z1,z2,z3)'=[102][0-11][234]*(y1,y2,y3),所以(z1,z2,z3)'=[102][0-11][234]
(线性规划)由条件当X=Y=3时有最大值Z=6即得K=3再由X+2Y>=0很容易求得Z最小值-3
∵x3y2+x2y3=x2y2(x+y),而x+y=-3,xy=-2,∴x3y2+x2y3=4×(-3)=-12.故答案为:-12.
(1)2a3b+8a2b2+8ab3=2ab(a2+4ab+4b2)=2ab(a+2b)2;(2)x3y2-4x2y+4x=x(x2y2-4xy+4)=x(xy-2)2;(3)9(a+b)2+12(a
小龙求出的值是6.5.计算如下:原式=3x2-4x3y2+3x2y+2x2+4x3y2+2x2y-5x2-5x2y+x-y+1=x-y+1,当x=2.7,y=-2.8时,原式=2.7-(-2.8)+1