Answer:
W = 3/2 n (Tâ- Tâ)
Explanation:
Let's use the first law of thermodynamics
      ÎE = Q + W
in this case the cylinder is insulated, so there is no heat transfer
      ÎE = W
internal energy can be related to the change in temperature
      ÎE = 3/2 n K ÎT
we substitute
      3/2 n (Tâ-Tâ) = W
as the work is on the gas it is negative
      W = 3/2 n (Tâ- Tâ)