计算:(1)-4x²y+2x²y+5y²x-2xy²(2)7-3x-4x

计算3x[xy-2x(1/y-x/3]+3y(x²-y²) 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) 计算x²y³-2x(4xy³) 多项式因式分解 1,(x-y)³-(x-y)²(x+y) 2,x(x²-xy)-(4x&# 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 计算 2xy[4x²y²-3y（xy+x²y）-xy²] 计算3x/8y×16y²/27x² （2xy-x²）÷x-2y/xy 2x-6/x (-x-2y)(x²-2xy+4y²) 计算：（-7x²y）（2x²y-3xy³+xy） 计算：(xy-x²)×x-y/xy 已知实数x,y满足5x²+2y²+1=6xy+4x-2y,则x²-xy+2000y 求3xy²-4x²y-2xy²+ 5x²y的值,其中x,y满足|x-1|+(y+