Cryptography is a study of coding and decoding messages. One type of coding process assigns a number to each letter of the alphabet and to the space character. For example:

A B C C D D E F $P,Q,R,S,T,U,V,W,x,Y,Z$ space

$1,2,3,4,5,6,7,8,9,10,11,12,13,14,15$

$16,17,18,19,20,21,22,23,24,25,26,27$

According to the numbers assigned to each letter, the message "Decimals have a point" would be coded as follow:

DECIMALS $-$ HAVE $\_A\_P$

$O$ I $N$ T

$1591420$

Now suppose each letter is encoded by applying a function such as $f(x)=2x+5$ where $x$ is the numerical value of each letter. For example:

The letter a will be coded as: $,f(1)=2(1)+5=7$

The letter $b$ will be coded as: $,f(2)=2(2)+5=9$

Using this encoding function we have:

Using this encoding function we have:

Message: D E C I M A L S $-$ H A V $E-A-P$ I $N$ T

Original: $4,5,3,9,13,1,12,19,27,8,1,22$

$527127161591420$

Coded form: $13151123317294359217$

$4915597593735233345$

To decode this message, the receiver would need to reverse the operations assigned by $f(x)=2x+5,$ since the function multiplies $x$ by $2$ and then add $5,$ we can reverse this process

by subtracting $5$ and then dividing by $2.$ This is represented by: $g(x)=\frac{x-5}{2}$

Encode your first and last name according to the function $f(x)=4x+2($use space between your Kelsy Melgarejo.$)$

Give the formula for decoding the message above $.$