Final answer:
The given equation is not invertible.
Step-by-step explanation:
The given equation is Y_t = 0.5Y_(t-1) - 0.5Y_(t-2) + e_t - 0.5e_(t-1) + 0.25e_(t-2). To determine if it is stationary or invertible, we need to check if all the coefficients are within the range of an invertible moving average (MA) process. For invertibility, the absolute value of the coefficient of all the lagged errors should be less than 1. In this case, the coefficient of e_t is 1, which is not less than 1. Therefore, the given equation is not invertible.