What is the first question? Did you switch places? Accompany?

If it is transposed, it is.

At:

three

2

1

2

four

2

six

seven

six

A+AT=

six

four

seven

four

eight

nine

seven

nine

12

A-AT=

five

five

-5

-5

AAT=

14

16

38

16

24

66

38

66

12 1

ATA=(AAT)T=

14

16

38

16

24

66

38

66

12 1

The second question. The solution is as follows: Find the rank of the coefficient matrix. r