2/(a²-4)*[(a²+4)/4a-1]=2/(a²-4)*[(a²+4-4a)/4a]=2/(a²-4)*(a²-4a+4)/4a=2/[(a-2)(a+2)]*(a-2)²/4a=1/(a+2)*(a-2)/2a=(a-2)/[2a(a+2)]=(a-2)/(2a^2+4)[a/(a-1)-1] /[1/(a²...