Example 5.2.6.

Solve the following congruences for \(x\text{.}\)

1. \(7x \equiv 12 \pmod{13}\text{.}\)

2. \(84x - 38 \equiv 79 \pmod{15}\text{.}\)

3. \(20x \equiv 23 \pmod{14}\text{.}\)