(2x+y-1)²=(2x+y)²-2(2x+y)+1=4x²+4xy+y²-4
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
已知X²+Y²+X²Y²-4XY+1=0 求:(X-Y)^2008-(XY)^2
多项式因式分解 1,(x-y)³-(x-y)²(x+y) 2,x(x²-xy)-(4x
2x+y=0,求4x²+2xy(x+y)+y³
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
若|x-2|+x²+1/4y²-xy=0 x= y=
已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
解方程x²-2xy+y²=9,x²+4xy+4y²+x+2y=2 2x-1/y=
已知实数x,y满足5x²+2y²+1=6xy+4x-2y,则x²-xy+2000y
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y