已知:x^2+xy=3,xy+y^2=-2.求(1)x^2-y^2 (2)x^2+4xy+3y^2 (3)2x^2-xy
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知x-y=4xy,则2x+3xy-2yx-2xy-y
x-y=1,xy=2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知:xy+x=-1,xy-y=-2,求多项式-x-[2y-2(xy+x)的平方+3x]+2[x+(xy-y)的平方]的
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知xy^2=-2 求-xy(x^2y^5-xy^3-y)
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
已知x-y=3,xy=1,求(-2x+2x+3y)-(3xy+2y-2x)-(x+4y+xy)