Respuesta :

a. The first variable is x and the second variable is y.

b. The equations are [tex]x+y=12[/tex] and [tex]x-y=8.[/tex]

Step-by-step explanation:

Step 1:

The first step is to define the variables. The variables can be any two symbols, letters, characters, etc.

Here let the first variable be x and the let the second variable be y.

So the variables are defined as x and y.

Step 2:

The sum of the given variables is 12.

The first variable + the second variable = 12,

[tex]x+y=12.[/tex]

The difference between the two variables is 4.

The first variable - the second variable = 4.

[tex]x-y=4.[/tex]

Step 3:

If we add both the equations we get, [tex]2x =16, x= 8[/tex] and [tex]y=4.[/tex]

x = 8 and y = 4.