The message 29 34 39 57 45 65 2 3 17 22 54 74 26 39 29 43 was encoded with matrix A. Decode the message. A = [1 2, 1 3]
The message is:.

The message is S  E  C R  E  T     A G E N T       M A N

Step-by-step explanation:

This is a very easy exercise, follow the steps taken below:

Step 1: Find

Note that If

then

Therefore,

Step 2: Find A⁻¹B ( i.e product of A and B)

Step 3: Decode the message in the matrix above

The message will be decoded in this order:

Note that 0 stands for  empty space

19 5 3 18 5 20 0 1 7 5 14 20 0 13 1 14

S  E  C R  E  T     A G E N T       M A N

The message encoded is:  S  E  C R  E  T     A G E N T       M A N