I can't understand exercise 4.23 in https://www.ssc.wisc.edu/~bhansen/econometrics/Econometrics.pdf

Can you tell me the solution?

And I don't know the rules of this website.

Can I ask you the solutions of problems not in Bruce Hansen Econometrics but related to ridge regression?

Exercise 4.23 Take the linear regression model with E [Y | X] = X6. Define the ridge regression estima- tor B = (X'X + IA) x'Y where 1 > 0 is a fixed constant. Find E [ B | X]. Is B biased for B