已知x²-y²+4x+2y=-3,且x+2y=5,求x和y
已知x²-y²+4x+2y=-3,且x+2y=5,求x和y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x,y为实数,且2(x+2y)=x²+y²+5求代数式3x-4y分之x²+y²
已知x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)
已知x²+y²-2x+4y+5=0,求x+y
已知x² +y²+5/4=2x+y,求y-x的值
已知x²+4x+y-2y+5=0求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-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x、y均为实数,且满足xy+x+y=17,x^2y+y^2x=66,求x^4+x^3y+x^2*y^2+y^3x+y