｛x+y=12 x-y=16

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 (12-2x)/X=(-16-2Y)/Y X^2+Y^2=25 Y 化简 x / y(x+y) - y / x(x+y) = (x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少 x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x.y都是自然数,且x(x-u)-y(y-x)+12,求x.y得值快1且x(x-y)-y(y-x)=12 ｛x+y=12 x-y=16 [(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11,y=1/12,化简再求值. x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? 8x-8y-3x-3y=-12,6x+6y-8x+4y=16 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 y=x(x (X,Y) f(x,y)={12y^2,0 12y(x-y)^2-8(x-y)^3=? 已知|x|+x+y=10 |y|+x-y=12 求 x+y=? 已知|x|+x+y=10,|y|+x-y=12,求x+y的值