[(x-√2y)(x-√2y)-(x-√2y)²+4y(y-x²)]÷2xy 其中x=√2-1/1,
[(x-√2y)(x-√2y)-(x-√2y)²+4y(y-x²)]÷2xy 其中x=√2-1/1,
先化简再求值 [(1/(x-y)+1/(x+y)]-【2y/(x的平方-2xy+y的平方)】 其中x=1+√2,y=1-
先化简,再求值(x-y/x+y)^2÷(y-x/x^2+2xy+y^2)^2*1/x+y,其中x=-4,y=1
数学题化简再求值(1/x-y+1/x+y)÷x^2 y^2/x^2-y^2,其中x=3,y=-√2
5x²-(3y²+5x²)+(4y²+7xy),其中x=-1,y=1-√2
[(x-2y)²-4y²+2xy]÷2x,其中x=2,y=1
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
[(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2
先化简,再求值:3x²—[2x²y—(xy—x²)]+4x²y,其中x=—1,y
先化简,再求值,x分之x-y÷(x-x分之2xy-y²)其中x=2,y=-1
(4x-2y-1)²+√xy-2=0,求4x²y-4x²y²+xy²
先化简再求值:(X-Y)分之1 -(X+Y)分之1)÷(X²+2XY+Y²)分之2y,其中x=√3+