3X²y-3y²X+2Xy²-2yX²当y=-2,X=3时.
3X²y-3y²X+2Xy²-2yX²当y=-2,X=3时.
3xy+xy+2x²y+yx²+3x²y等于多少
已知x-y=4xy,则2x+3xy-2yx-2xy-y
x²-3xy-3x²y²+2yx²-y²x 合并同类项
.先化简,后计算.[2x(x²y-xy²)+xy(xy-x²)]/x²yx=20
6x²y+2xy-3x²y²-7x-5yx-4y²x²-6x²
求6x²y+2xy-3x²y²-7x-5yx-4y²x²-6x
实数x、y、z满足x=6-3yx+3y-2xy+2z
已知y=3xy+x,求代数式2x+3xy−2yx−2xy−y
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
(x³-2xy²)dy+(2y³-3yx²)dx=0求通解
化简、、、最好有过程x²y-3xy²+2yx²-y²x2、(3a²-a