divide and check

t^2 - 13
---------
t - 4

Using synthetic(long-hand) division and

get:

(t^2 - 13) / (t-4) = t+4, Re = 3.

Check: (t-4)(t+4) + 3 = t^2-16 + 3 = x^2-13.

I can't show synthetic division here.