Question

How to find the inverse x of: 3x ≡ 1 mod 3 ?

Answer 1

x = (4/3)

Answer 2

in general, the modular inverse y, of x in mod z is:
\[yx = 1 (\mod z)\]
sorry for equals sign, but I can't find congruent

Answer 3

so,
\[y = \frac{z+1}{x}\]