A square matrix N is called nilpotent if there exists some positive integer k such that Nk = 0. Prove that if N is a nilpotent matrix, then the system Nx = 0 has nontrivial solutions.

The average hourly earnings for a construction worker is projected to be $24.50 in 2012. jason wants to join the construction work force after he graduates in 2012. his friend tells him that average hourly earnings for construction workers will rise by 2% from 2009 to 2012. based on the data below, assuming that the projected hourly earnings are correct, is jason’s friend’s statement accurate? construction industry - average hourly earnings, 2000-2009 a. his friend’s statement is accurate. the average hourly earnings will increase by 2%. b. his friend’s statement is not accurate. the percent increase will be more than 2% c. his friend’s statement is not accurate. the percent increase will be less than 2% d. his friend’s statement is not accurate. the average hourly earnings will decrease

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.