x+y=80 求X Y的值

x+y=80 求X Y的值 x+x+x+y+y=54 x+x+y+y+y=56 求y的值 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知|x|+x+y=10,|y|+x-y=12,求x+y的值 已知|x|+x+y=10,x+|y|-y=12,求x、y的值 已知/x/+x+y=10,/y/+x-y=12.求x+y的值 y=3(x-y),x=2(x-y)求x,y的值 已知x-y=8,（x+y)(x-y)=32,求x,y的值 X+Y-8X+10Y+41=O,求X/Y-Y/X的值 若x-y=1,求代数式x(x-y)+y(y-x)+2013的值 x,y 满足x(x-2)-y(y-6)=-10,求x,y的值 (x+y)+(x-y)+(x/y)+(x*y)=1998求xy的值 正数x,y满足x-y=2xy,求x-y/x+y的值. 已知|3x-y|+|x+y|=0,求x-y除以x*y的值. 已知x≠y,x^2-x=y^2-y,求x+y的值. 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 x/3=y/4,求(x*x-xy)/(x*x+y*y)的值