(-x^2+3xy-0.5y^2)-(0.5x^2+4xy-1.5y^2)=-0.5x^2+( )+y^2
(x+2y-3y)- (-2x-y+xy ) 其中x+y=0.5 xy等于-0.5
xy-[x+2y+0.5(x-4)*(y-2)]
(-3x^y+2xy)-( )=4x^+xy
(xy-x^2)乘以(xy)/(x-y)
(-x^2+3xy-0.5y^2)-(0.5x^2+4xy-1.5y^2)=-0.5x^2+( )+y^2
已知x-y=4xy,则2x+3xy-2yx-2xy-y
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
利用x-y=3^2009,xy=-3^2010,求代数式:(2x+3y-2xy)-(x+4y+xy)-(3xy+2y-2
(x^2+xy/x-y)/(xy/x-y)计算
已知x-y=4,xy=-2,求代数式(2x+3y-2xy)-(x+4+xy)-(3xy+2y-2x)的值
已知x+xy=-2,xy-y=-6求代数式2x{-4y-3[(x+xy)²+x]-½[(y-xy