(2X-3Y)(?)=-4X^+9Y^````

3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 9y=3x-(x-1),4(x+y)-(2x+4)=8y 根据3（x+y)-2(x-y)=11,4(x+y)+3(x-y)=9可得出x+y= ,x-y= 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 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 3(x+y)+2(x-y)=36 4(x+y)-5(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)-4(x-y)=11,2(x-y)+5(x+y)=27 (2X-3Y)(?)=-4X^+9Y^```` 如果x+y/2=x-y/3=3x-2y+9/4,那么x= ,y=如果x+y/2=x-y/3=3x-2y+9/4,那么x= ,y= (x-y)/4+(x+y)/5=1/4 (x+y)/9-(x-y)/3=//2(x-y)/4+(x+y)/5=1/4(x+y)/9-(x-y)/3=//2