Matrix multiplication was used to encode a message using the given encoding matrix: [i 47 A=1 |-1 -3] The original message was c
onverted to row matrices of size: 1x 2 and each was multiplied by A. sp 0 A 1 B 2 C 3 D 4 E F G H I J K L M N O P Q R 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 14 | 15 | 16 | 17 | 18 S T U V W X Y Z 19 20 21 22 23 24 25 26 Coded message: 11 52 -8 -9 -13 -39 5 20 12 56 5 20 -2 7 9 41 25 100 Find A and use it to decode the message
We can check that in fact A*A^⁻1=I_2 the identity matrix of size 2 x 2.
Now the message was divided in 1 x 2 matrices, then we have that the sequence given is the result of multiplying m by A, so to get m again we multiply now by A^⁻1. and we get the next table
Encoded message Decoded message message in letters by association