3x-7y=-24 x+y=12

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 解方程组24/(x+y) +24/(x-y) = 7/3 ,8/(x+y) +18/(x-y) = 4/3 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 x-2y=9 x+y+z=7 2x-3y=12 若x+7y=y-3x，求x 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) (x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少 若3x=7y,则y分之x= ,x:（x:y）= 若3x=7y,则y比x= ,x:（x+y）= 3y=2x y/3=x/2 12/x=9/y y/x=?y/x=?x/y=? 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y除以2x-y