令m=1995
(1995^2-2*1995-1993)/(1995^3+1995^2-1996)
=(m^2-3m+2)/(m^3+m^2-m-1)
=[(m-1)(m-2)]/[m^2(m+1)-(m+1)]
=[(m-1)(m-2)]/[(m+1)^2(m-1)]
=(m-2)/(m+1)^2
=1993/1996^2
=1993/3984016
令m=1995
(1995^2-2*1995-1993)/(1995^3+1995^2-1996)
=(m^2-3m+2)/(m^3+m^2-m-1)
=[(m-1)(m-2)]/[m^2(m+1)-(m+1)]
=[(m-1)(m-2)]/[(m+1)^2(m-1)]
=(m-2)/(m+1)^2
=1993/1996^2
=1993/3984016