（3x^y-2x+1)(-2xy)(2x-1)(x-3)-3a(a-b)^2(x-2)(x-3)-(x+5)(x-5)(a+2b-3c)(a-2b-3c)(2a+b)^2(2a-b)^2因式分解4a^2-16-2x^2-12xy^2+8xy^3a^2-4(a-b)^24x(a-b)-8y(b-a)(a+3b)^2-9(a-b)^2(x^2-5)^2+8(x^2-5)+16(a^2+b^2)^2-4a^2b^225(a+b)^2-9(a-b)^2

计算3xy[2xy-x(y-2)+x-1] 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 计算：1-2x+x^2/x-x^3*xy+x^2y/x-x^2 因式分解x^2y^2+x^2y+xy^2+3xy+x+y+1 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y .(x+y-2)(x+y-2xy)+(xy-1)^2 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² 因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) (x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)答案应为-2x-x*x-3x， (-1/3xy)^2•[xy(2x-y)-2x(xy-y^2)] xy(xy+1)+xy+3-2(x+y+1/2)-(x+y-1)^2因式分解 (-3分之1xy)的平方×[xy(2x-y)-2x(xy-y的平方)] -xy^2(x+y)^3+x(x+y)^2因式分解 XY(XY+3)+(XY+4)+4(X+Y+1)-(X+Y+2) 计算：(5-xy/x^3-x^2y)/(1-5/xy)^2*(y-x)^3 (x+3y)/(x^2+xy)-x+y计算题 计算3x[xy-2x(1/y-x/3]+3y(x²-y²) x²-y²+5x+3y+4（x+y-2xy)(x+y-z)+(xy-1）²