-4x^2*(1/2xy-y^2)-3(xy^2-2x^2y)
(xy-x^2)乘以(xy)/(x-y)
(x+y-2xy)(x+y-2)+(1-xy)²
计算3xy[2xy-x(y-2)+x-1]
(-3x^y+2xy)-( )=4x^+xy
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
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