-2x^3y+2x^2y^2-1/2xy^3
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
计算3xy[2xy-x(y-2)+x-1]
(x+y)(x-y)-(2xy+3y)平方
[x(x^2y^2-xy)-y(x^2-x^3y)]/3x^2y
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
【(x-y)^3(x^1/2+y^1/2)^-3+3(x根号y-y根号x)】/(x根号x+y根号y)+(2xy根号xy-
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)]
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
1/2xy-{1/2xy-[1/3x^2y-(x^2y-xy)]+1/3x^2y}
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2