已知x+y=10,x^3+y^3=400,求x^2+y^2
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y)
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y
已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值.
已知x+y分之x-y=2,求2x+2y分之x-y-3x-3y分之2x+2y的值
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y除以2x-y
已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值