9x^2-6x-y^2+4y-3 过程谢谢

81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 计算(x-y)^7÷(y-x)^6+9-x-y)^3÷(x+y)^2 4x-3y/x-2y÷6y-8x/y-2x （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 （y-x）^4（x-y）^3+2（x-y）^6（y-x） 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) (66x^6y^3-24x^4y^2+9x^2y)÷(-3x^2y)化简 解二元一次方程 {3(x+y)-4(x-y)=-9 x+y/2+x-y/6=1 4x-y/2根号x+根号y 9x-6根号xy+y/3根号x-根号y x^3y^2+6x^2y+9x 常微分方程的通解dy/dx=(x-y+1)/(x+y-3)y^4=2y^n+y=0y''+6y'+9y=e^(-3x)y''+y'-2y=4e^(2x)