x+y/2+ x-y/2=6 2(x+y)-3x+3y=24 求X Y

已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 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 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 当2x-y/x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的值. 当2x-y\x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的値.