2. Convert the congruence equation into a system of congruence equations to solve:
(i) $23 x \equiv 1(\bmod 140)$;
(ii) $17 x \equiv 229(\bmod 1540)$.
2. (i) $x \equiv -1(\bmod 4), 2x \equiv -1(\bmod 5), 2x \equiv 1(\bmod 7)$, the solution is $x \equiv 67(\bmod 140)$;
(ii) $x \equiv 1(\bmod 4), 2x \equiv -1(\bmod 5), 3x \equiv 5(\bmod 7), 2x \equiv 3(\bmod 11)$, the solution is $x \equiv 557(\bmod 1540)$