化简求值[(x+y)²-(x-y)²+4x²y²]÷4xy,x=(√2)°,y=
化简再求值[(x²+y²)²-4x²y²]÷(x²-y&su
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的
x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy
先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·
x²+y²+4x-8y+20=0,求(x²-y²)÷xy的解
先化简,再求值:(x²)/(x²-2xy+y²)÷(x²+2xy+y²)/(x&
先化简 再求值.4x²-8xy+4y²/ 2x²-2y² 其中 x=2 y=3
①先化简,再求值.4(3x²y—1/2xy²)—5(—xy²+3x²y),其中x
3x²-4xy+y²
2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y
化简求值(3x-4y)²-(3x+4y)²-xy,其中x=1,y=-1
化简并求值:4x ³(-y ³)² -3x 乘(-x)²(-y²)&s