(-1/2x^2·y)^3·(-3xy^2)^2
计算3xy[2xy-x(y-2)+x-1]
计算:(2分之1x^(2)y-2xy+y^(2))·3xy
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)]
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
5x^2y/-1/2xy*3xy^2
y^3+xy^2+2xy+x^2-1 因式分解
先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·
1/2xy-{1/2xy-[1/3x^2y-(x^2y-xy)]+1/3x^2y}
化简!1、(x^2-xy)+xy+y^2 2、3(x^2-xy)-xy+y^2
(x+2y-3xy)-(-2x-y+xy),其中x+y=1/2,xy=-1/2