Let A = [๐๐๐] be a square matrix of order 3×3 and |A|= -7. Find the value of
๐
11
๐ด
21
+ ๐
12
๐ด
22
+ ๐
13
๐ด
23
where ๐ด
๐๐
is the cofactor of element ๐
๐j