化简:(1)(-2xy)[(3x^2)-2xy-(4y^2)]
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
化简!1、(x^2-xy)+xy+y^2 2、3(x^2-xy)-xy+y^2
计算3xy[2xy-x(y-2)+x-1]
(-3x^y+2xy)-( )=4x^+xy
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
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
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2
已知x-y=4xy,则2x+3xy-2yx-2xy-y
xy(xy+1)+(xy+3)-2(x+y+2分之一)-(x+y-1)的平方
(-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)]