4x-4y=5-3y x分之2 y分之3=2
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∵x2+y2-2x-4y+5=0,∴x2-2x+1+y2-4y+4=0,(x-1)2+(y-2)2=0,∴x=1,y=2,∴yx−xy=2-12=1.5;故答案为:1.5.
6x^2y+2xy-3x^2y^2-7x-5yx-4y^2x^2-6x^2y,=-7x^2y^2-3xy-7x其中|x+3|+(y-2)^2=0即x+3=0,y-2=0x=-3,y=2原式=-7*9*
∵x+y=4,xy=3,∴原式=x2+y2xy=(x+y)2−2xyxy=16−63=103.
∵3x-5y=0,∴x=5y3,∴原式=5y3−2y5y3+3y=-111.
7x的立方y的平方,8x的立方y,2分之1x的平方y的平方,-3yx的平方z,9x的4次方zy,zy的平方,-5分之1xyz,9y的立方z,0.3z的立方一共是九项,因为9y的立方z不含x,所以所有含
2x+yx2-2xy+y2•(x-y)=2x+y(x-y)2•(x-y)(2分)=2x+yx-y;(4分)当x-3y=0时,x=3y;(6分)原式=6y+y3y-y=7y2y=72.(8分)
原式=[(x+y)2(x-y)(x+y)+-4xy(x-y)(x+y)]×(x+3y)(x-3y)(x+3y)(x-y)=x-3yx+y,由已知得(3x-2y)(x+y)=0,因为x+y≠0,所以3x
∵2x−yx+y=3,∴2x-y=3x+3y,x=-4y,(2x−3y)3−(3x−2y)3(4x+2y)3−(x−7y)3=(−11y)3−(14y)3(−14y)3−(−11y)3=-1.故选A.
似乎题目应该是y=√(x-2)+√(2-x)+4x-2>=02-x>=0x=2代入得y=4yx=4*2=8y的x次=4²=16
其实第一步就是立方差的公式,你记住就可以了.(x^3+y^3==(x+y)(x^2-yx+y^2)是立方和的公式).而第二步就是括号里运用配方的方法就可以得到了.蛮简单的.而且高中学习里面很少用到第二
(1)x=4代入,4+y=4y-2y;所以y=4(2)y=4代入,4+4=4x-2*4;所以x=4
-x^2y+4x^2y-3yx^2-7x^2y^2+|-8x^2y^2|=-x²y+4x²y-3x²y-7x²y²+8x²y²=(
∵x-y=4xy,∴2x+3xy-2yx-2xy-y=2(x-y)+3xyx-y-2xy=8xy+3xy4xy-2xy=112.故答案为:112.
6x^2y+2xy-3x^2y^2-7x-5yx-4y^2x^2-6x^2y=6x^2y-6x^2y+2xy-5yx-3x^2y^2-4y^2x^2-7x=-3xy-7x^2y^2-7x
你抄错题了吧X2+Y2+5/4=2X+Y移项,得(X-1)2+(Y-1/2)2=0X=1,Y=1/2
解答如下:x+2y=(yx)/44x+8y=xyxy-8y=4x(x-8)y=4x当x≠8时(x=8不成立)y=4x/(x-8)x+2y=(2x+1)/32y=(2x+1)/3-x2y=(1-x)/3
代入y=5/4原方程可化为:x/4+5/4=5/4(x-2)等号两端同乘以4x+5=5x-104x=15x=15/4再问:若三分之x+2=x则x-()=2再答:移项,x-x/3=2所以()中填x/3
6x²y+2xy-3x²y²-7x-5yx-4y²x²-6x²y|x+3|+(y+1/2)²=0x=-3y=1/2=-3xy-7x
化简:[(y²-x²)/(5x²-4yx)]/[(x+y)/(5x-4y)]原式=[(y+x)(y-x)/x(5x-4y)]×[(x+y)/(5x-4y)]=(y-x)/