1.(x-y)(x2+xy+y2) 2.求值x2(x-1)-x(x2+x-1),其中x=2分之一

(x-y)(x2+xy+y2) (x+y)(x2-xy+y2) 1.(x-y)(x2+xy+y2) 2.求值x2(x-1)-x(x2+x-1),其中x=2分之一 因式分解x2+y2-xy-x-y+1 x2-4y2-3xy+y+x (x-y)(x2+xy+y2)-xy(y-x) 4x2-y2/x2-2xy+y2 +(2x-y)/2x2-2xy 计算(x+y/x-y + 4xy/y2-x2)(x2-9y2)/（x2+2xy-3y2） 1.已知正数x,y满足x2-y2=2xy,求(x-y)/(x+y)的值2.若x2+xy-2y2=0则(x2+3xy-2y2)/x2-2y2)=_________3.先化简,后求值：(3-x)/(x-2)除以（x+2-2/(x-2)）,其中x=2√2  已知实数x,y满足x2+xy+y2=3,则x2-xy+y2的最小值 已知(x2+y2)=1.(x2-y2)=81,求x2+y2与xy(x+y)2=1.(x-y)2=81,求x2+y2与xy的值 2是平方 x2-2xy+y2=4 x2+y2-x-y=6 解不等式x2-2xy+y2=4 x2+y2-x-y=6 解不等式 1*{x+y+xy=7{x2+y2+xy=132*{x2+y2=10{x+xy+y=7 已知x2+4y2+x2y2+1=6xy,则(x4-y4)/(2x2+xy-y2)*(2x-y)/(xy-y2)/(x2+y2/y)2= x2+y2 xy+x+y-1x y属于R 比较大小 x2+y2 xy+x+y-1 [2/xy/(1/x+1/y)2+(x2+y2)/(x2+2xy+y2)]*2x/(x-y) （x+y）（x2次方-xy+y2次方） 2x2+xy-y2-4x+5y-6 因式分解