Construct a random 4 x 4 matrix A and test whether (A + I) (A - 1) = A² - I. The best way to do this is to compute (A + 1)(A - 1) - (A² - I) and verify that this difference is the zero matrix. Do this for three random matrices. Then test (A + B)(A - B) = A² - B² the same way for three pairs of random 4 x 4 matrices. Report your conclusions.