X[X/(Y+X)+X/(X-Y)]=120/288
X[X/(Y+X)+X/(X-Y)]=120/288
2.(x+y)²(x-y)²-(x-y)(x+y)(x²+y²)
{(x,y) |x|+|y|
x>y?x:y
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
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
用行列式性质计算(需过程):(x,y,x+y; y,x+y,x; x+y,x,y )
(x-y/x+2y)³
-{-[-(x-y)]}+{-[(x+Y)]}
若3x=7y,则y分之x= ,x:(x:y)=
若3x=7y,则y比x= ,x:(x+y)=
y=2x*(*代表X)