Вариант 7 ИДЗ 1.1

DHS - 1.1
No. 1.7. For this determinant find the minors and algebraic additions.
Calculate the determinant: a) spreading it over the elements of the i line; b) spreading it out
j column elements; c) having previously received zeros in the i line. i = 2; j = 3.
No. 2.7. Two matrices A and B are given. Find: a) AB; b) BA; c) A – 1; d) AA – 1; e) A – 1A.