Вариант 2 ИДЗ 1.1

DHS - 1.1
No. 1.2. For this determinant, find the minors and algebraic additions. Calculate the determinant: a) by expanding it into the elements of the i line; b) spreading it into j column elements; c) having previously received zeros in the i line. i = 3; j = 3.
№ 2.2. Two matrices A and B are given. Find: a) AB; b) BA; c) A – 1; d) AA – 1; e) A – 1A.