The problem of unique ranking turns out to be easier to address if the link matrix is stochastic. If A is the link matrix to a web with n documents, and more selected numbers like 0  
 2) Write down the Google matrix M when the link matrix A is the one you found in Problem 2, and m is selected equal to 0.1. Use the Matlab command null to determine the null space of M - I. Then enter the unique score vector of M.
 
Matrix A from problem 2:
 
A = (0, 0, 1/2, 0), (1/3, 0, 0, 0), (1/3, 1/2, 0, 0), (1/3, 1/2, 1/2, 0)
 
 
 
I appreciate your help! 
 
Thank you!