The solution manual provides a step-by-step solution to these problems and many more.
Using the formula for gain:
Find the current through a silicon diode with a given voltage. The solution manual provides a step-by-step solution to
A_v = -Rf / Rin
100 = -100 * 1 kΩ / (Rin + 25 Ω)
Solving for Rin: