\ 4 In school, Jack and Sam exchanged notes in a code

f

which consists of spelling every word backwards and interchanging every letter

s

with

t

. Alternatively, they use a code

g

which interchanges the letters a with

o

, i with

u

, e with

y

, and

s

with

t

. Describe the codes

f@g

and

g@f

. Are they the same?

Find gf. Explain why fg is undefined. 4 In school, Jack and Sam exchanged notes in a code f which consists of spelling every word backwards and interchanging every letter s with t. Alternatively, they use a code g which interchanges the letters a with o, i with u, e with y, and s with t. Describe the codes fg and gf. Are they the same