已知2x3y=2,求9

已知x=√3-√2,y=√3+√2,求x3y+xy3x3y+xy3=xy(x^2+y^2)=(√3-√2)(√3+√2)((√3-√2)^2)+(√3-√2)^2)=1*(3-2√6+2+3+2√6+2)=10

已知x-y=-6,xy=-8,求x3y-2x2y2+xy3的值x³y-2x²y²+xy³=xy(x²-2xy+y²)=xy(x-y)²=-8×(-6)²=-8×

已知：x+y=二分之一,xy=1.求x3y+2x2y2+xy3的值 

已知x=根号3+根号2,y=根号3－根号2,求x3y+xy3

已知x+y=5,xy=3,求代数式x3y-2x平方y平方+xy3已知x+y=5,xy=3,代数式x3y-2x平方y平方+xy3=xy(x²-2xy+y²)=xy(x-y)²=3×[(x+y)²-4xy

已知x+y=4,xy=2,则x3y+x2y2+xy3的值:x+y=4,xy=2后者平方后二式相加再加后者平方x3y+x2y2+xy3=xy(x2+xy+y2)=xy[(x+y)2-xy]=2×[4平方-2]=2×14=28

已知实数xy满足条件|2x-3y+1|+(x3y+5)的二次方=0求式子（-2x*y）的二次方（-y的二次方）×6xy平方的值∵|2x-3y+1|+(x+3y+5)的二次方=0∴2x-3y+1=0x+3y+5=0x=-2y=-1∴（-2x*

x3y-x2y2+2xy3=xy指的是3xy-2x2y+2x3y=xy莫?数字写在后面都指的是前面字母的几次方

已知:|x+y+1|+|xy-3|=0,求代数式xy3+x3y的值.∵|x+y+1|≥0,|xy-3|≥0|x+y+1|+|xy-3|=0,∴x+y+1=0,即x+y=-1xy=3xy3+x3y=xy(x²+y²)=yx

已知x-y=1,求代数式x4-xy3-x3y-3x2y+3xy2+y4x4-xy3-x3y-3x2y+3xy2+y4=(X^4-X^3Y)-(XY^3-Y^4)-(3X^2Y-3XY^2)=X^3(X-Y)-(X-Y)Y^3-3XY(X-Y

如果x+y=2xy=2,求1/2x3y+x2y2+1/2xy3的值.x+y=2两边同时平方得x²+2xy+y²=4所以x²+y²=4-2xy=4-2×2=01/2x3y+x2y2+1/2xy3=1/2

已知关于x,y的方程组2x3y=-k+2,3x-2y=5k+3的解x,y的值满足x-y=5,求k的值.最后答案是k=2.2x+3y=-k+2,①3x-2y=5k+3②2*①+3*②13x=13k+13所以x=k+1代入①y=-kx-y=2k

已知:4X-3Y-6Z=0,X+2Y-7Z=0(XYZ不等于0),求X+5Y+7Z/2X3Y+6Z的值把z看作常数{4x-3y=6z{x+2y=7z解之得{x=3z{y=2z把x=3z,y=2z代入X+5Y+7Z/2X+3Y+6Z=3z+1

已知(3x+2y-5)²与|5x3y-8|互为相反数,依题意得3x+2y-5=05x+3y-8=0联立两个方程得x=1y=1(3x+2y-5)²≥0|5x-3y-8|≥0由于(3x+2y-5)²与|5x3y-8

已知(3x-2y-5)²与|5x3y-8|互为相反数,已知(3x-2y-5)²与|5x+3y-8|互为相反数那么3x-2y-5=0,5x-3y-8=0解方程组得x=1,y=-1两个式子互为相反数，则它们的和为0.所以3x

求x3y-xy3x3y-xy3=xy(x^2-y^2)=xy(x+y)(x-y)xy(x+y)(x-y)

3x2-12x,x2-6x+9,16m5-m,x3y-2x2y2+xy33x2-12x,=3x(x-4)x2-6x+9,=x²-2×x×3+3²=(x-3)²16m5-m,=m(16m的4次方-1)=m(4m&

14．已知x、y均为实数,且满足xy+x+y=17,x2y+xy2=66,求x4+x3y+x2y2+xy3+y4的值.已知x、y均为实数,且满足xy+x+y=17,x2y+xy2=66,求x4+x3y+x2y2+xy3+y4的值.由已知：x

已知x、y均为实数,且满足xy+x+y=17,x2y+xy2=66,求：代数式x4+x3y+x2y2+xy3+y4的值．详细点由已知：xy+x+y=17,xy(x+y)=66,可知xy和x+y是方程x2-17x+66=0的两个实数根,得：x

已知x、y均为实数,且满足xy+x+y=17,x2y+xy2=66,求x4+x3y+x2y2+xy3+y4的值.x^2y+y^2x=xy(x+y)=66令xy=t1x+y=t2则t1+t2=17t1t2=66所以t1,t2为方程t^2-17