4x^2+y^2+4xy+12x-6y+9=0如题..应该没错，如果错了，老师会说

因式分解:12xy^2(y-x)+xy^3(x-y)+4x^2y(x-y) 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 2X^+XY-Y^-4X+5Y-6 2x^+xy-y^-4x+5y-6=? (x+y)(x+y+2xy)+(xy+1)(xy-1)(x+y)(x-y)+4(y-1) 5x^3y*(-3y)^2+(-6xy)^2*(-xy)+xy^3*(-4x^2) 计算:2xy/(x+y)².(x+y)/4y 1-2/x+y=xy,4y+6x=xy.求xy的解? xy-2{xy-[3x^2y-(4xy^2+0.5xy)]+4x^2y}+6xy^2 因式分解：x(y-3)-(2y-6) (x+y)^3-(x-y)^2(x+y) x(x^2-xy)-(4x^2-4xy) 分解公因式分解 x(y-3)-(2y-6) 2.(x+y)^3-(x-y)^2(x+y) 3.x(x^2-xy)-(4x^2-4xy) （X-3xy+4xy-y）-[-2x-2（xy-3/2xy）-y]+6xy的过程 诺x+y=6,xy=4 求(5x-4y-3xy)-(8x-y+2xy) (x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy) x^+2xy+y^+4=16 x^-2xy+y^=16 求(3xy+6y^)+|x^-(2xy+2y^-3x^)|的值 化简求值x-4y/2x-7xy+3y×x-2xy-3y/2x+3xy-2y÷3x-6y/4x-4xy+y,其中：x=1999,y=-1 2(x*x-3xy-2y*y+2)- =-4y*y-6xy+3x X×X-2XY-Y×Y+2X-2Y+2=02X×2X-4XY-2Y×2Y+3X-3Y+4=0X×X+2XY+Y×Y+X+Y-56=0X×X-2XY+Y×Y-X+Y-12=0X×X-3XY+Y×Y=-13X×3X-XY+3Y×3Y=13 两个在一起的方程之间有所联系（要求一步一步写出来）