Hi, I need help with my statistics exercise. Please answer the problem a, b, c, and does the results hold. I will upvote if the answer is correct. Thank you!

Exercise 2 Consider the regression model yi = Bo + Bidi + ci, i = 1,..., n. The Gauss-Markov conditions hold. Let Bo and B1 denote the OLS estimates of Bo and B1. Then the ith residual is ei = yi - Bo - Biti. Show that a. 2. i= 1 ei = 0. b. Ereixi = 0. heyi = 0. Do these results also hold for the model yi = Bidi + ci, i = 1, ...,n