{x y=4,2x 3y=7
已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y
{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)-4(x-y)=11,2(x-y)+5(x+y)=27
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
(x+y)(x+2y)(x+3y)(x+4y)=-40
4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y
已知X和Y满足3X+4Y=2,X-Y-1/7
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y