:[(x-2/x+2)+(4x/x^2-4)]÷(1/x^2-4)
=[(x-2)/(x+2)+(4x/x^2-4)]×(x^2-4)
=(x-2)/(x+2)×(x^2-4)+(4x/x^2-4) ×(x^2-4)
=(x-2)²+4x
=x²+4
当x=-5时
原式=(-5)²+4
=29
:[(x-2/x+2)+(4x/x^2-4)]÷(1/x^2-4)
=[(x-2)/(x+2)+(4x/x^2-4)]×(x^2-4)
=(x-2)/(x+2)×(x^2-4)+(4x/x^2-4) ×(x^2-4)
=(x-2)²+4x
=x²+4
当x=-5时
原式=(-5)²+4
=29