(1)xv2/(xv2-4)÷(2+x)/(xv2-2x)-1/(x-2)

问题描述:

(1)xv2/(xv2-4)÷(2+x)/(xv2-2x)-1/(x-2)
(2)12/(mv2-9)+2/(3-m)+2/(m+3)
补充:我知道这两题的答案:1题是2/(x-2)v2;2题是0.我现在只要知道它是怎么做出来的,

(1)xv2/(xv2-4)÷(xv2-2x)/(2+x)-1/(x-2)
=x²/(x-2)(x+2)*(x+2)/x(x-2)-1/(x-2)
=x/(x-2)²-1/(x-2)
=x/(x-2)²-(x-2)/(x-2)²
=(x-x+2)/(x-2)²
=2/(x-2)²
(2)12/(mv2-9)+2/(3-m)+2/(m+3)
=12/(m-3)(m+3)-2(m+3)/(m-3)(m+3)+2(m-3)/(m-3)(m+3)
=(12-2m-6+2m-6)/(m-3)(3+m)
=0/(m-3)(m+3)
=0