画（3x+4y-2）^2+(4x-5y+7)=1的图像,为什么老是有错误呢?th = (linspace(0,2*pi,100))';X=(5*cos(th)+4*sin(th)-18)/31;Y=1/2+cos(th)/4-3*(5*cos(th)+4*sin(th)-18)/31;polt(X,Y,'linewidth',2)看到了，那这道题可以用plot函数吗？如

（x-y）^3×（y-x）^4+（x-y）^2×（y-x）^5 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) [(x+y)(x-y)-(x-y)的平方+2y(x-y)]除以(4y)请帮我一下写两道计算题[(x+y)(x-y)-(x-y)的平方+2y(x-y)]除以(4y)[（3x+2y）（3x-2y）-（x+2y）（5x-2y）]除以（4x） 5/4(x+y)(-x-y)^3*[-4/3(x-y)]*[-3/5(y-x)^2] (2x-y)(3x-4y)-2(x-y)(2x-5y)简便运算 5x^3y(x-y)^3-10x^4y^3(y-x)^2因式分解 5x^3y(x-y)^3-10x^4y^3(y-x)^2 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 （y-x）^4（x-y）^3+2（x-y）^6（y-x） 5X^3Y(X-Y)-10X^4Y^3(Y-X)^2因式分解 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) 12（x+y）^3（y-x）/【4（x+y）^2(x-y)】 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 2分之x+y+3分之x-y；4（x+y）-（x-y)谢谢了, 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) 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 3(x-y)-2(x+y)-5(x-y)+4(x+y)+3(x-y) 化简合并同类项