2x^2y*A=(-6x^3y^2+9X^2y^3 ,求A=?

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 如果A={（x,y）|x,y+2>0},B={（x,y）|2x+3y-6>0},C={（x,y）|x-4 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 （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)-2(x-y)=11 4(x+y)+3(x-y)=9 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 计算(x-y)^7÷(y-x)^6+9-x-y)^3÷(x+y)^2 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 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 1、(-y^3)^5/y^3/ y^2+2(-y)^102、(x-y)^7/(y-x)^6+(x+y)^3/(x+y)^23、已知X^a=5,x^b=3,求X^(3a-2b)的值