用两种方法计算：（X-2分之3X）-（X+2分之X）乘于X分之(X的平方-4）

[3x/(x-2)-x/(x+2) ]*(x²-4)/x 乘法分配律 (a+b)*c=ac+bc
=[3x/(x-2)]*(x²-4)/x-[x/(x+2) ]*(x²-4)/x
=3(x+2)-(x-2)
=2x+8
[3x/(x-2)-x(x+2) ]*(x²-4)/x 通分
={[3x(x+2)-x(x-2)]/(x+2)(x-2)}*(x²-4)/x
=[(3x²+6x-x²+2x)/(x²-4)]*(x²-4)/x
=2x+8

-(X/2) - 3/2 (-4 + X^2)