3x^2y-[2xy^2-2(xy-3/2x^2y)+xy]+3xy^2,X=3y=-1/3(化筒求植,
(-3x^y+2xy)-( )=4x^+xy
已知x-y=4xy,则2x+3xy-2yx-2xy-y
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
计算3xy[2xy-x(y-2)+x-1]
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
x-y=1,xy=2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值