Answer: PARALLEL LINES should be coded as "TSHSRRUR RWFUO"
Step-by-step explanation:
Since we have given that
PARALLEL LINES
As we know that according to alphabets,
P is at 16
A is at 1
R is at 18
L is at 12
E is at 5
N is at 14
S is at 19
And we have given that
[tex]c \equiv(7p+12)\ mod 26[/tex]
So, P becomes :
[tex]c\equiv (7\times 16+12)\ mod\ 26=124\ mod\ 26=20\ mod\ 26=T[/tex]
A becomes
[tex]c\equiv (7\times 1+12)\ mod\ 26=19\ mod\ 26=S[/tex]
S becomes
[tex]c\equiv (7\times 19+12)\ mod\ 26=145\ mod\ 26=15\ mod\ 26=O[/tex]
L becomes
[tex]c\equiv (7\times 12+12)\ mod\ 26=96\ mod\ 26=18\ mod\ 26=R[/tex]
E becomes
[tex]c\equiv (7\times 5+12)\ mod\ 26=47\ mod\ 26=21\ mod\ 26=U[/tex]
I becomes
[tex]c\equiv (7\times 9+12)\ mod\ 26=75\ mod\ 26=23\ mod\ 26=W[/tex]
N becomes
[tex]c\equiv (7\times 14+12)\ mod\ 26=110\ mod\ 26=6\ mod\ 26=F[/tex]
R becomes
[tex]c\equiv (7\times 18+12)\ mod\ 26=138\ mod\ 26=8\ mod\ 26=H[/tex]
Hence, PARALLEL LINES should be coded as "TSHSRRUR RWFUO"