(1-5/x)^(2*x)
((1 - 1*5)/x)^(2*x)
(1 - 5/x)^(2*x)
2*x / 5\ lim |1 - -| x->oo\ x/
Limit((1 - 5/x)^(2*x), x, oo, dir='-')
-10 e