先化简,再求值:(x²)/(x²-2xy+y²)÷(x²+2xy+y²)/(x&
先化简,再求值:(x²)/(x²-2xy+y²)÷(x²+2xy+y²)/(x&
先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·
①先化简,再求值.4(3x²y—1/2xy²)—5(—xy²+3x²y),其中x
先化简,再求值:(x+y)(x-y)+(x-y)² -(6x² y-2xy² )/2y其中
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的
x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy
1-x²+2xy-y²
化简再求值[(x²+y²)²-4x²y²]÷(x²-y&su
计算:3(2x²-3xy²)-2(2xy²-3x²y)
计算:(1).(-2xy²)*(3x²y)²
越快越好(1)(xy²+3)(xy²+3)-2x(-x+y)(2)(x+2)(x²+4)(
先化简 再求值.4x²-8xy+4y²/ 2x²-2y² 其中 x=2 y=3