1 3x²+4xy-y²=
1 3x²+4xy-y²=
3x²-4xy+y²
计算:(1).(-2xy²)*(3x²y)²
方程组{x²+y²=10(1)x²-3xy+2y²=0(2)怎么解
1.已知3x²-xy+y²=10,-xy+4y²=4,则x²-y²的值
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的
已知x-2y=3,x²-2xy+4y²=11,求①xy ②x²y-2xy²
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y.若x
越快越好(1)(xy²+3)(xy²+3)-2x(-x+y)(2)(x+2)(x²+4)(
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若|
设A=2x²-3xy+y²-x+2y ,B=4x²-6xy+2y²+3x-y .
先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·