X+X+Y+Y+Y=56,X+X+X+Y+Y=54.X=?Y=?XY=?
解方程x*x+xy=y+y*y
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
根据x+x+x+y+y=54,x+x+y+y+y=56,求出x.y的值
x>1,y>0,且满足xy=x^y,x/y=x^3y,求x+y
已知x+y=-5,x*x+y*y=19求xy和(x-y)*(x-y)的值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
x,y都是自然数,且x(x-y)-y(y-x)=12,求x+y-xy的值
已知XY.Y=-3,求-XY(X.X.X.Y.Y.Y.Y.Y.Y.Y-3.X.X.Y.Y.Y.Y.Y-Y)的值.(过程完
有这样一道题,计算:(x-y)[(x+y)(x+y)-xy]-(x-y)[(x-y)(x-y)+xy]的值,其中x=20
有这样一道题:计算(x-y)[(x+y)(x+y)-xy]+(x+y)[(x-y)(x-y)+xy]的值,其中x=200
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
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*