若X^2-y^2=48,x+y=4,则x=?,y=?

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 若X^2-y^2=48,x+y=4,则x=?,y=? 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-x)= 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若2x=3y,则(x*x+y*y)/x*x=? 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x-4y)(2x+y)= 若x=2012,y=2013,则(x+y)×[(x^2+y^2)/x^4-y^4)] 若5x+3y=3x+4y=x+2y+6,则x+y=___ x^2-y^2=48,x+y=4,则x=?y=? 若X+Y=8,(X-Y)^2=4,则X^2+Y^2= 若x/y=4/3 则3x+2y/2x-5y= 若|x+y+4|=-(x-y)4次方,则(-2y)平方x=