先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·
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
3x²-4xy+y²
x³y³-x²y²-xy+1
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的
先化简 再求值.4x²-8xy+4y²/ 2x²-2y² 其中 x=2 y=3
先化简,再求值:(x²)/(x²-2xy+y²)÷(x²+2xy+y²)/(x&
已知x/y=3,求x²+2xy-3y²/x²-xy+y³的值
计算:(1).(-2xy²)*(3x²y)²
因式分解:m³-2m²-4m+8;x²-2xy+y²-9
1-x²+2xy-y²
x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy