$4x \equiv 12 \pmod {26}$
I have this equation and I understand that it has two solution via $\text{gcd}(26, 4)$. One of the answers is $x\equiv3$, which I can get by multiplying both sides by inverse of $4$. But the other answer which is $x\equiv16$.
I don't understand how to get this. Is it something to do with getting a general equation? Bezout's identity?
$$4x\equiv12\pmod{26}\iff2x\equiv6\pmod{13}$$
$$\implies x\equiv3\pmod{\frac{13}{(13,2)}}$$
$$\implies x\equiv3\pmod{13}$$
See Property $\#12$ of Congruence