Вариант 27 ИДЗ 1.1

DHS - 1.1
No. 1.27. For this determinant find the minors and algebraic additions.
Calculate the determinant: a) spreading it over the elements i of the string; b) spreading it into j column elements; c) having previously received zeros in the i line. i = 3; j = 4.
No. 2.27. Two matrices A and B are given. Find: a) AB; b) BA; c) А⁻¹; d) AA⁻¹; d) A⁻¹A.